WO2025008324A1

WO2025008324A1 - Modular building unit

Info

Publication number: WO2025008324A1
Application number: PCT/EP2024/068553
Authority: WO
Inventors: Edward Ross SHENTON; David Lee JONES
Original assignee: Sano Development Ltd
Current assignee: Sano Development Ltd
Priority date: 2023-07-05
Filing date: 2024-07-02
Publication date: 2025-01-09
Anticipated expiration: 2026-01-05
Also published as: WO2025008330A1; WO2025008332A1; WO2025008334A1; WO2025008327A1; WO2025008328A1; WO2025008319A1; WO2025008325A1; WO2025008335A1

Abstract

There is disclosed a modular building unit (10), a modular building assembly (12) comprising the modular building unit, a building (28) comprising the modular building unit/assembly, and a method of constructing a building comprising the modular building unit. The modular building unit (10) comprises a structural frame (16). The structural frame comprises: a floor frame portion (18) having a first depth (D₁), the floor frame portion configured to support a planar floor structure (104); a ceiling frame portion (20) having a second depth (D₂); and a support structure (22) extending between and connecting the floor frame portion to the ceiling frame portion. A ratio of the first depth (D₁) of the floor frame portion relative to the second depth (D₂) of the ceiling frame portion is at least about 1:3. The modular building unit defines a circulation space (42) configured to provide at least one access function for a building comprising the modular building unit. The building can be a hybrid residential building comprising a first building section (36) and a second building section (38). The first building section is an on-site construction at a final building location (40). The second building section comprises the modular building unit (10). The first and second building sections are connected at the final location to form the building.

Description

MODULAR BUILDING UNIT

The present invention relates to a modular building unit, a modular building assembly comprising a modular building unit, a building comprising the modular building unit/assembly, and a method of constructing a building (particularly a hybrid building) comprising a modular building unit. In particular, but not exclusively, the present invention relates to a modular building unit comprising a structural frame having a floor frame portion, a ceiling frame portion, and a support structure extending between and connecting the floor frame portion to the ceiling frame portion.

Prefabricated buildings (also known as ‘modular’ buildings) are well known in the construction industry, particularly modular residential buildings such as houses, flats or apartments, and hotels. Modular buildings typically comprise a series of building units which are constructed in a factory, transported to a final location (or site) for the building, and then arranged in a predetermined configuration and coupled together to form the finished building. The modular building units are typically constructed to a substantially assembled form in the factory, in which they can be transported to the final location. Construction of the building can involve stacking one or more upper modular building unit on a lower such unit, so that the upper unit is supported by the lower unit.

Hybrid buildings have been developed by the applicant which comprise a first building section that is constructed at a final location for the building, and a second building section comprising one or more modular building unit constructed in a dedicated facility, away from the final location. A hybrid building of this type can provide advantages including that: construction of the first building section is simplified, with more complex parts of the building provided in the section formed by the modular building unit(s); and the first building section can provide the primary living space in the building, without being constrained by construction and transport limitations imposed on the modular building unit(s). The hybrid buildings and associated construction techniques are disclosed in International patent publication nos. WO2022/243696, WO2022/243695, WO2022/243694, WO2022/243693 and WO2023/222853.

Most modular building units comprise a structural frame including a floor portion, a ceiling portion, and a support structure which serves to connect the ceiling portion to the floor portion, and to transmit structural loading from the ceiling portion to the floor portion. The modular building units are typically generally quadrilateral-shape in plan view (e.g. rectangular). The support structure includes support posts or columns which extend between the floor and ceiling portions. Support posts are typically provided at comers of the unit, with additional posts positioned around its perimeter. The support structure can also include transverse bracing stmts extending between at least some of the support posts. Walls are formed by connecting wall panels or sheets to the support posts. Options for the support structure include a metallic frame, which can be cold- formed (e.g. of light gauge steel), hot formed (e.g. of hot rolled steel), or combinations of the two. A hot- formed metallic frame may provide a sufficiently rigid structure so that additional perimeter support posts and bracing stmts can be dispensed with (or the number of posts/struts reduced). Other options include timber-based frames. The floor portions of conventional modular building units are relatively deep (considered in a vertical sense), and often have depths which are greater than their ceiling portions. The floor portions usually comprise a frame formed from a number of beams and/or joists, which can have a depth of perhaps 30cm (almost 12”) or more. It has conventionally been necessary to provide such a deep floor frame because modular building units forming a lowermost storey or floor of a building are often positioned on a concrete foundation. A thick layer of insulation material must be therefore accommodated within the floor portion itself, in order to reduce thermal energy transfer between the foundation and the modular building unit. It has also been considered necessary to provide a deep floor frame, to provide rigidity to the structure, including for transport.

Modular building units having deep floor frames can cause problems in hybrid buildings of the type described above, including that matching a floor level of the building section formed from the modular building unit(s) with that formed by the section constructed at the final building location can be challenging. In addition, the ceiling frames of known modular building units can also be relatively deep. Where modular building units are stacked to form a multi-storey building, this can result in a very deep structure at the intersection between the ceiling of a lower unit, and the floor of an upper unit. This complicates the transition for a staircase between the units, and also impacts on material usage, weight and costs. It will be understood that these can also be issues in fully modular buildings, including that steps must be taken to accommodate the deep floor during the construction process.

According to a first aspect of the present invention, there is provided a modular building unit comprising a structural frame, the structural frame comprising: a floor frame portion having a first depth, the floor frame portion configured to support a planar floor structure; a ceiling frame portion having a second depth; and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which a ratio of the first depth of the floor frame portion relative to the second depth of the ceiling frame portion is at least about 1 :3; and in which the modular building unit optionally defines a circulation space configured to provide at least one access function for a building comprising the modular building unit.

The depth of the floor and ceiling frame portions may be considered or measured in a generally vertical direction. Reference may alternatively be made to vertical heights of the floor and ceiling frame portions (and/or parts of same).

The provision of a modular building unit having the stated depth relationship may provide particular benefits in the context of a hybrid building of the type described above. This includes facilitating matching a floor level of a building section comprising the modular building unit with a floor level of a section of the building constructed at its final location. For example, both the section formed by the modular building unit, and the section constructed at the final location, may rest on a common foundation. It may be desirable to maintain common (or uniform) floor levels within the constructed building, to avoid a change in floor height between the building sections. Providing floor and ceiling frame portions with such a depth relationship may have the result that the floor frame portion depth can be relatively shallow, so that only a small height difference need be accommodated. This may provide additional benefits in terms of material and cost savings. In addition, arranging the floor and ceiling frame portions so that they have depths in the stated ratio may have the result that the ceiling frame portion can be made to be relatively deep, without adversely impacting the depth of the floor frame portion. This may enable the ceiling frame portion to provide a majority of the structural strength for the modular building unit, and space to accommodate e.g. utilities/building services equipment such as: wastewater conduits for wet facilities provided in an upper modular building unit stacked on a lower such unit; water supply conduits; ventilation conduits; electrical power and communication cables. The shallow floor frame portion may also help to reduce a depth of structure at the intersection between the ceiling of a lower modular building unit and the floor of an upper such unit.

The ratio of the first depth relative to the second depth may be up to about 1 :6. The ratio of the first depth relative to the second depth may be in a range of between about 1 :3 to about 1 :6. A ratio falling within this range may provide a good balance of a relatively thin floor frame portion, and a ceiling frame portion that can provide a majority of the structural strength for the modular building unit and/or space to accommodate required utilities/building services equipment. The ratio may however be in excess of 1 :6, and may for example be up to around 1 : 7, or up to around 1 :8.

The first depth of the floor frame portion may be up to about 70mm (-2.756”). A floor frame portion having such a depth may be relatively shallow, and may be significantly shallower than floor frame portions of conventional modular building units. In a hybrid building comprising a first section constructed at a final location, and a second section comprising the modular building unit, a level of a floor of the first section may be brought up to that of the second section by applying e.g. a cementitious screed to a floor support structure of the first section. It may be preferred to restrict the first depth to no more than around 70mm, which may be a maximum optimal height for such a screed. The first depth may be up to around 50mm (~1.968”). The first depth may be in a range of about 50mm to about 70mm. A depth in the region of around 50mm may be preferred.

The second depth of the ceiling frame portion may be at least about 150mm (-5.906”). The second depth may be up to about 300mm (-11.811”), optionally up to around 350mm, and optionally up to around 400mm. The second depth may be in a range of about 150mm to about 300mm. A depth in the region of about 250mm to about 260mm may be preferred.

A modular building unit having such floor and ceiling frame portion first and second depths may provide a good balance of benefits, e.g. in terms of minimising disruption to accommodate the floor frame portion and/or minimising a depth of structure at a transition between lower and upper modular building units, whilst providing a sufficiently strong ceiling frame portion and/or depth in the ceiling frame portion to accommodate utilities/building services equipment.

The first depth of the floor frame portion may be defined by a part or parts of the floor frame portion that are in a load path. The second depth of the ceiling frame portion may be defined by a part or parts of the ceiling frame portion that are in a load path. The load path (which may be a direct load path) may be a path of loading transmitted (or passing) from the ceiling frame portion through the support structure to the floor frame portion, during normal use of the modular building unit. The load path may be for loading transferred from a further (e.g. upper) modular building unit stacked or seated on the modular building unit, and/or self-loads of the modular building unit. For the purposes of the present analysis, the depth relationship between Di and D2 may be determined based on the structure that is in or on such a load path. Accordingly, Di may be based on a depth or height of a part or parts of the floor frame portion that are on or in the load path, whilst D2 may be based on a depth or height of a part or parts of the ceiling frame portion that are on or in the load path.

The modular building unit may be generally quadrilateral-shape in plan view, may be generally rectangular, and may be generally cuboid.

The floor frame portion may comprise a floor frame. The first depth of the floor frame portion may be defined or described by the floor frame. The floor frame may have an upper surface. The floor frame may have a lower surface. The first depth may be defined between the upper and lower surfaces. The floor frame may comprise, and/or may be formed from or defined by, a plurality of elongate frame members. The elongate frame members may define the upper and/or the lower surfaces. The floor frame may comprise a perimeter frame structure (or loop member/structure), which may comprise elongate beams. The perimeter frame structure may comprise first and second side beams, which may be disposed substantially parallel to one another. The perimeter frame structure may comprise first and second end beams, which may be disposed substantially parallel to one another. The first and second side beams, and the first and second end beams, may together form or define a majority or all of the perimeter frame structure. The floor frame may comprise at least one support beam, which may extend in a direction between the first and second end beams, and disposed between the side beams. The floor frame may comprise at least one support beam, which may extend in a direction between: the first and second side beams; or one of the first and second side beams and the support beam extending between the end beams. The floor frame may comprise a plurality of elongate joists. At least one joist may extend in a direction between the first and second side beams. At least one joist may be arranged to have a depth which is different to (e.g. less than) the depth of beams forming the perimeter frame structure (said beams being of the first depth).

The floor frame may be configured to support the planar floor structure. The planar floor structure may define a floor of the modular building unit. The planar floor structure may comprise, or may be defined by, one or more planar floor panel. The first depth of the floor frame portion may not include said planar floor structure, other structural or insulative material positioned on said floor structure, and/or any decorative floor finish or covering (e.g. carpet or tiles) positioned on said floor structure. The ceiling frame portion may comprise a ceiling frame. The second depth of the ceiling frame portion may be defined or described by the ceiling frame. The ceiling frame may have an upper surface, which may be configured to support a further modular building unit stacked or seated on the modular building unit. The ceiling frame may have a lower surface, which may be seated on the support structure. The second depth may be defined between the upper and lower surfaces. The ceiling frame may comprise, and/or may be formed from or defined by, a plurality of elongate frame members. The elongate frame members may define the upper and/or the lower surfaces. The ceiling frame may comprise a perimeter frame structure, which may comprise elongate beams. The perimeter frame structure may comprise first and second side beams, which may be disposed substantially parallel to one another. The perimeter frame structure may comprise first and second end beams, which may be disposed substantially parallel to one another. The first and second side beams, and the first and second end beams, may together form or define a majority or all of the perimeter frame structure. The ceiling frame may comprise at least one support beam which may extend in a direction between the first and second end beams, and disposed between the side beams. The ceiling frame may comprise a plurality of elongate joists. At least one joist may extend in a direction between the first and second side beams. At least one joist may be arranged to have a depth which is different to (e.g. less than) a depth of beams forming the perimeter frame structure.

The ceiling frame portion may comprise at least one mounting member, and may comprise a plurality of mounting members. The mounting member may serve for mounting a further (e.g. upper) modular building unit on the modular building unit. The at least one mounting member may protrude or extend from an upper surface or extent of a frame member or members forming part of the ceiling frame. The at least one mounting member may extend upwardly and/or in a generally vertical direction, optionally away from the upper surface/extent of the ceiling frame member(s). The at least one mounting member may take the form of a block, post, stub, pin or P^eg-

The at least one mounting member, in particular an upper surface of said mounting member, may be configured to contact a lower surface of a further (e.g. upper) modular building unit stacked or seated on the modular building unit, in particular a lower surface of a floor frame of said further unit. This may provide the advantage that a void, space or gap can be formed between the two modular building units using the at least one mounting member, which may accommodate e.g. utilities/building services equipment such as sewerage conduits as discussed above. Said void can be created with minimal additional structure, and so cost and weight savings. The second depth may be defined between the upper surface of the mounting member(s) and a lower surface of the ceiling portion (which may be defined by the ceiling frame, in particular by lower surfaces of its elongate frame members). The at least one mounting member may be coupled to, or provided by (e.g. integral to), the ceiling frame. There may be a plurality of mounting members, which may be spaced apart around the perimeter of the modular building unit defined by the ceiling frame. A mounting member may be provided at each comer of the modular building unit, which comers may be defined by the ceiling frame. The ceiling frame portion may comprise a plurality of mounting members. An aperture may be provided between an adjacent pair of mounting members, through which utilities/building services equipment can pass. A plurality of apertures may be provided, each aperture defined between an adjacent pair of mounting members. The ceiling frame portion may comprise, or may define, a load transfer section. The load transfer section may be configured to transfer load to the support structure. The load may be that imparted by a further (e.g. upper) modular building unit, which may be stacked or seated on the modular building unit.

The load transfer section may comprise the ceiling frame. The load transfer section may comprise the at least one mounting member.

The ceiling frame portion, in particular its ceiling frame, may be configured to support a planar ceiling structure. Said planar ceiling structure may define a ceiling of the modular building unit. Said planar ceiling structure may comprise, or may be defined by, one or more planar ceiling panel. The second depth of the ceiling frame portion may not include said planar ceiling structure, other structural or insulative material connected to said planar ceiling structure, and/or any decorative finish or covering (such as a cementitious coating) applied to said planar ceiling structure.

Reference is made in this document to a ceiling frame portion of the modular building unit, and to a ceiling of the unit. Reference to a ceiling frame portion (and a ceiling) should be taken to mean an upper structure which covers or encloses an internal volume of the modular building unit. It will be understood that the ceiling frame portion of the modular building unit will not typically provide a weather-resistant roof structure intended to prevent e.g. water ingress into the modular building unit. For example, a roof structure may be formed separately and positioned above the modular building unit in order to weatherproof it. However, the modular building unit could optionally provide such a roof, for example by arranging the ceiling frame portion to additionally provide or define an external or outer roof for the unit. This may be an option particularly e.g. for single storey buildings comprising the modular building unit, or where the unit forms an uppermost storey of a building. Suitable options can include a flat roof structure.

The ceiling frame portion may comprise structural (e.g. elongate) frame members. The ceiling frame portion, in particular the load transfer section, may take the general form of a lattice or lattice type structure. The ceiling frame portion, in particular the load transfer section: may comprise a lower structural member, which may define a lower surface of the load transfer section; may comprise an upper structural member, which may define an upper surface of the load transfer section; and may comprise at least one connecting member, which may extend between and connect the lower structural member to the upper structural member. The at least one connecting member may serve for transferring loads from the upper structural member to the lower structural member, and so to the support structure. There may be a plurality of connecting members. At least one connecting member may take the form of a strut, which may be disposed substantially perpendicular to a main axis of the upper and/or lower structural member. At least one connecting member may take the form of a brace, which may be disposed transverse to a main axis of the upper and/or lower structural member, suitably at an angle other than 90°. The ceiling frame portion, in particular the load transfer section, may comprise a plurality of generally elongate parts, which may together define the load transfer section. The support structure may define a plurality of walls of the modular building unit, which may be external walls (e.g. at, or defining at least part of, a perimeter of the unit). A generally elongate part may be provided for each wall. The generally elongate parts may each be seated on a respective wall. The generally elongate parts may each be disposed transverse to (optionally substantially perpendicular to) at least one adjacent generally elongate part. Each generally elongate part may comprise respective lower and upper structural members, and at least one connecting member extending between and connecting the lower and upper structural members. The upper structural members of the elongate parts may together form a perimeter frame (or loop member), which may be an upper perimeter frame. The lower structural members of the elongate parts may together form a perimeter frame (or loop member), which may be a lower perimeter frame.

The services aperture may be defined by or between structural members of the ceiling frame portion. The at least one aperture may be defined between at least some of the lower and upper structural members and the connecting members.

The ceiling frame portion, in particular the load transfer section, may comprise a lower surface, which may be seated on an upper surface or surfaces of the support structure. The load transfer section may comprise an upper surface, which may be configured to support a further (e.g. upper) modular building unit.

The ceiling frame portion, in particular the load transfer section may have, or may be of, a height (which may be a first height). The height may be defined between the upper and lower surfaces of the load transfer section. The (first) height may be in the range of about 200mm to about 300mm, optionally up to around 350mm, and optionally up to around 400mm. A (first) height in the region of about 250mm to about 260mm may be preferred.

The ceiling frame portion may comprise a ceiling section, which may be configured to define or support a ceiling of the modular building unit. The ceiling section may be disposed inwardly of the load transfer section and may be connected to it. The ceiling section may comprise a lower surface, which may be disposed at a position that is lower than the upper surface of the support structure, in particular walls of/defined by the support structure.

The ceiling frame portion may define the services void. The services void may comprise an upper boundary, which may be defined or formed by a plane containing the upper surface of the load transfer section. The services void may comprise a lower boundary, which may be defined or formed by a plane containing the lower surface of the ceiling section. The services void may be defined between a plane containing the upper surface of the load transfer section, and a plane containing the lower surface of the ceiling section. The services void may have, or may be of, a height (which may be a second height). The height of the void may be greater than the height of the load transfer section. The (second) height may be in the range of about 250mm to about 350mm, or greater. A (second) height in the region of about 275mm to about 295mm may be preferred.

The ceiling section may comprise an upper surface, which may be disposed at a position that is lower than (and/or may be below) the upper surface of the load transfer section. The ceiling section may have, or may be of, a height (which may be a third height). The height may be defined between the upper and lower surfaces of the ceiling section. The height of the ceiling section may be less than the height of the load transfer section. The third height may be less than both the first and second heights. The (third) height may be in the range of about 70mm to about 100mm. A (third) height in the region of about 75mm to about 95mm may be preferred.

A height of the services aperture is dictated by structural features of the ceiling frame portion, and dimensions of structural members, but may be in the region of about 120mm to about 175mm, with a dimension of perhaps 150mm to 160mm being preferred.

The ceiling section may depend from the load transfer section so that the ceiling section overlaps a top part of the support structure, in particular a wall or walls defining the upper surface.

The load transfer section may form an outer part of the ceiling frame portion. The load transfer section may define at least part of an outer perimeter of the ceiling frame portion. The load transfer section may comprise a perimeter structure, which may extend around a perimeter of the modular building unit. The ceiling section may form an inner part of the ceiling frame portion. The ceiling section may be disposed inwardly of the load transfer section in that it may be disposed within the outer perimeter. The load transfer section may define or comprise an inner perimeter. The ceiling section may be positioned within the inner perimeter. The ceiling section may extend below the load transfer section within the inner perimeter.

The load transfer section, and/or the ceiling section (in particular their structural frame members) may be formed from any suitable material and construction technique, but may in particular be cold-formed (e.g. folded) metallic members, such as of a light gauge steel material (forming a light gauge steel frame or LGSF).

Reference is made to upper and lower surfaces of features of the modular building unit(s). It will be understood that such surfaces are considered to be upper or lower in a vertical sense, during normal use of the modular building unit(s). Thus an upper surface of the respective feature can be considered to be at a position which is higher than that of a lower surface, considered in a vertical direction. Reference may also be made to the heights of features. Similarly, such heights may be measured/considered in a vertical sense, during normal use of the modular building unit(s).

The second depth of the ceiling frame portion may not include the ceiling section (which may support or define the ceiling). The second depth may be defined or described by the load transfer section. The second depth may be defined or described by a part or parts of the ceiling frame portion which are generally in line with, and/or seated on, the support structure (in particular a wall or walls defined or described by the support structure).

The support structure may comprise at least one support post or column, and suitably comprises a plurality of support posts or columns. Support posts/columns may be provided at one or more comer of the modular building unit, in particular at one or more comer of the floor frame portion. At least one support post/column may be provided at a location on a perimeter of the floor frame portion which is spaced from one or more of the corners. The support structure may comprise bracing or support members which may extend transversely between a pair of adjacent support posts/columns. Other options for the support structure exist, including structural insulated panels (SIPs), and other panels e.g. of a cement-based material.

The access function provided by the circulation space (which may also be referred to as a circulation zone or transition space/zone) may be selected from the group comprising: access between upper and lower living spaces of the building (e.g. provided by upper and lower storeys of the building), optionally via a staircase or a lift shaft and lift, provided at least partly in the modular building unit; access between a first living space and at least one further living space of the building, said living spaces optionally being isolated from one another within another part of the building and optionally on a same level/storey (e.g. via a hallway /landing and one or more doorway or walkway provided at least partly in the modular building unit); and access into the building from an exterior of the building (e.g. via one or more doorway or walkway, and optionally also a hallway, provided by the modular building unit).

The circulation space may be defined wholly by the (or a) modular building unit. For example, where the circulation space provides access from the outside of the building, the space may be defined wholly by a single such unit. The circulation space may be defined in combination by a plurality of modular building units. For example, where the circulation space provides access between upper and lower living spaces, two or more units may cooperate to define the access, e.g. each may form part of a staircase or lift shaft.

The at least one modular building unit may define (and suitably may completely or entirely define) at least one room, and may define a plurality of rooms. The at least one modular building unit may comprise an internal volume, and the room(s) may be defined within, and may accommodate part of, said volume. The at least one modular building unit may be arranged so that it comprises one or more wall, which may define a boundary or boundaries (optionally all boundaries) of said room. At least one room may contain a wet facility, which may be selected from the group comprising a bathroom, a shower room, an ensuite, a W/C or washroom, and a utility room. One or more further room of the plurality of rooms may be arranged to contain a wet facility.

The at least one modular building unit may be arranged to define at least part of a perimeter of the building, which may be an external perimeter. The modular building unit may comprise one or more wall, and a wall or walls of the modular building unit may be arranged to define said part of the perimeter. The wall or walls may be arranged so that an external surface of the wall or walls defines an external surface of the building, or may be clad or surfaced with an exterior surface finish/coating (e.g. panels, bricks slips, cementitious render). According to a second aspect of the present invention, there is provided a modular building assembly comprising: a first modular building unit; and a second modular building unit positioned on the first modular building unit so that the second modular building unit is supported by the first modular building unit; in which the first modular building unit comprises a structural frame, the structural frame comprising: a floor frame portion having a first depth, the floor frame portion configured to support a planar floor structure; a ceiling frame portion having a second depth; and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which a ratio of the first depth of the floor frame portion relative to the second depth of the ceiling frame portion is at least about 1 :3; and in which the modular building unit optionally defines a circulation space configured to provide at least one access function for a building comprising the modular building unit.

The first modular building unit may have any of the further features set out above in relation to the first aspect. The second modular building unit may be a modular building unit according to the first aspect, and so may have any of the further features set out above.

According to a third aspect of the present invention, there is provided a building comprising the modular building unit of the first aspect, or the modular building assembly of the second aspect.

The building may be a hybrid building, in particular a hybrid residential building, comprising a first building section and a second building section. The first building section may be an on-site construction at a final location for the building. The second building section may be defined by and/or may comprise the modular building unit of the first aspect, or the modular building assembly of the second aspect. The first and second building sections may be configured to be connected at the final location to form the building.

The building may be a modular building comprising a plurality of modular building units (at least one of which is the modular building unit according to the first aspect), or at least one (and optionally a plurality) of modular building assemblies according to the second aspect. An internal volume of the building, optionally excepting an upper or outer roof of the building, may be formed entirely by said units/assembly or assemblies.

The building may comprise a foundation comprising a load bearing structure and thermal insulation. The modular building unit/assembly may be located on the foundation so that the load bearing structure provides structural support for the modular building unit/assembly, and so that the thermal insulation thermally insulates the modular building unit/assembly relative to the ground. The circulation space (which may also be referred to as a circulation zone or transition space/zone) may be arranged to provide one or more access function selected from the group comprising: access between upper and lower living spaces of the first building section (e.g. between upper and lower storeys of the section, via a staircase, or a lift shaft and lift); access between a first living space and at least one further living space of the first building section, said living spaces optionally being isolated from one another within the first building section and optionally on a same level/storey of the section (e.g. via a hallway /lan ding and one or more doorway or walkway); and access into the first building section from the outside of the building, and so access into the building from its exterior (e.g. via one or more doorway or walkway, and optionally also a hallway).

The modular building unit may have any of the further features set out above in relation to the first aspect.

According to a fourth aspect of the present invention, there is provided a method of constructing a hybrid building comprising the steps of: constructing a first building section at a final location for the building; at a location away from the final location, constructing a modular building unit according to the first aspect of the invention to a substantially assembled form; transporting the modular building unit to the final location in the substantially assembled form, and arranging the modular building unit to form at least part of a second building section of the building; and connecting the first and second building sections to form the building.

The building may be a hybrid residential building.

The method may comprise constructing a foundation for the building, which may comprise providing the foundation with a load bearing structure and thermal insulation. The method may comprise locating the at least one modular building unit on the foundation so that the load bearing structure of the foundation provides structural support for the modular building unit, and so that the thermal insulation of the foundation thermally insulates the modular building unit relative to the ground. The method may comprise arranging the first building section so that it is supported by the foundation.

The method may comprise arranging the modular building unit so that it forms a planar floor structure of the second building section, and may comprise providing the planar floor structure with an upper support surface. The method may comprise forming the planar floor structure by positioning a planar floor panel or panels on the floor frame portion of the modular building unit, and arranging said panel so that it forms the upper support surface.

The method may comprise providing the first building section with a floor, and may comprise providing the floor with an upper support surface. The method may comprise arranging the floor of the first building section so that its upper support surface is at a common or uniform height with the upper support surface of the modular building unit. The method may comprise providing the floor of the first building section with a depth equivalent to the first depth of the modular building unit plus a depth of the planar floor structure of the modular building unit.

Further features of the method may be derived from the text set out elsewhere in this document, including in any of the other disclosed aspects, particularly in or with reference to any one or more of the first to third aspects.

According to a fifth aspect of the present invention, there is provided a modular building unit comprising a structural frame, the structural frame comprising: a floor frame portion configured to support a planar floor structure, the floor frame portion having a depth of up to about 70mm (2.756”); a ceiling frame portion having a depth of at least about 150mm (5.906”); and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which the modular building unit optionally defines a circulation space configured to provide at least one access function for a building comprising the modular building unit.

The depth of the floor and ceiling frame portions may be considered or measured in a generally vertical direction. Reference may alternatively be made to vertical heights of the floor and ceiling frame portions.

The provision of a modular building unit having the stated depth relationship may provide particular benefits in the context of a hybrid building of the type described above. This includes facilitating matching a floor level of a building section comprising the modular building unit with a floor level of a section of the building constructed at its final location. For example, both the section formed by the modular building unit, and the section constructed at the final location, may rest on a common foundation. It may be desirable to maintain common (or uniform) floor levels within the constructed building, to avoid a change in floor height between the building sections. A floor frame portion having such a depth is relatively shallow, which may have the result that only a small height difference need be accommodated. This may provide additional benefits in terms of material and cost savings. In addition, the ceiling frame portion can be made to be relatively deep, without adversely impacting the depth of the floor frame portion. This may enable the ceiling frame portion to provide a majority of the structural strength for the modular building unit, and space to accommodate e.g. utilities/building services equipment such as wastewater conduits for wet facilities provided in an upper modular building unit stacked on a lower such unit. The shallow floor frame portion may also help to reduce a depth of structure at the intersection between the ceiling of a lower modular building unit and the floor of an upper such unit.

The depth of the floor frame portion may be a first depth and the depth of the ceiling frame portion may be a second depth. A ratio of the first depth of the floor frame portion relative to the second depth of the ceiling frame portion may be at least about 1 :3. The ratio of the first depth relative to the second depth may be up to about 1 :6. The ratio of the first depth relative to the second depth may be in a range of between about 1 : 3 to about 1 :6. A ratio falling within this range may provide a good balance of a relatively thin floor frame portion, and a ceiling frame portion that can provide a majority of the structural strength for the modular building unit and/or space to accommodate required utilities/building services equipment. The ratio may however be in excess of 1 :6, and may for example be up to around 1 :7 , or up to around 1 :8.

A floor frame portion having the stated depth may be significantly shallower than floor frame portions of conventional modular building units. In a hybrid building comprising a first section constructed at a final location, and a second section comprising the modular building unit, a level of a floor of the first section may be brought up to that of the second section by applying e.g. a cementitious screed to a floor support structure of the first section. Restricting the depth of the floor frame portion to no more than around 70mm may be beneficial, as this may be a maximum optimal height for such a screed. The depth may be up to around 50mm (~1.968”). The depth may be in a range of about 50mm to about 70mm. A depth in the region of around 50mm may be preferred.

The depth of the ceiling frame portion may be up to about 300mm (~11.811”). The depth may be in a range of about 150mm to about 300mm, optionally up to around 350mm, and optionally up to around 400mm. A depth in the region of about 250mm to about 260mm may be preferred.

A modular building unit having such floor and ceiling frame portion depths may provide a good balance of benefits, e.g. in terms of minimising disruption to accommodate the floor frame and/or minimising a depth of structure at a transition between lower and upper modular building units, whilst providing a sufficiently strong ceiling frame portion and/or depth in the ceiling frame to accommodate utilities/building services equipment.

The depth of the floor frame portion may be defined by a part or parts of the floor frame portion that are in a load path. The depth of the ceiling frame portion may be defined by a part or parts of the ceiling frame portion that are in a load path. The load path (which may be a direct load path) may be a path of loading transmitted (or passing) from the ceiling frame portion through the support structure to the floor frame portion, during normal use of the modular building unit. The load path may be for loading transferred from a further (e.g. upper) modular building unit stacked or seated on the modular building unit, and/or self-loads of the modular building unit. For the purposes of the present analysis, the depths may be determined based on the structure that is in or on such a load path. Accordingly, the depth of the floor frame portion may be based on a depth or height of a part or parts of the floor frame portion that are on or in the load path, whilst the depth of the ceiling frame portion may be based on a depth or height of a part or parts of the ceiling frame portion that are on or in the load path.

The floor frame portion may comprise a floor frame. The depth of the floor frame portion may be defined or described by the floor frame. The floor frame may have an upper surface. The floor frame may have a lower surface. The depth may be defined between the upper and lower surfaces. The floor frame may comprise, and/or may be formed from or defined by, a plurality of elongate frame members. The elongate frame members may define the upper and/or the lower surfaces. The floor frame may comprise a perimeter frame structure (or loop member/ structure), which may comprise elongate beams. The perimeter frame structure may comprise first and second side beams, which may be disposed substantially parallel to one another. The perimeter frame structure may comprise first and second end beams, which may be disposed substantially parallel to one another. The first and second side beams, and the first and second end beams, may together form or define a majority or all of the perimeter frame structure. The floor frame may comprise at least one support beam which may extend in a direction between the first and second end beams, and disposed between the side beams. The floor frame may comprise at least one support beam, which may extend in a direction between: the first and second side beams; or one of the first and second side beams and the support beam extending between the end beams. The floor frame may comprise a plurality of elongate joists. At least one joist may extend in a direction between the first and second side beams. At least one joist may be arranged to have a depth which is different to (e.g. less than) the depth of beams forming the perimeter frame structure (said beams being of the stated depth).

The floor frame may be configured to support the planar floor structure. The planar floor structure may define a floor of the modular building unit. The planar floor structure may comprise, or may be defined by, one or more planar floor panel. The depth of the floor frame portion may not include said planar floor structure, other structural or insulative material positioned on said floor structure, and/or any decorative floor finish or covering (e.g. carpet or tiles) positioned on said floor structure.

The ceiling frame portion may comprise a ceiling frame. The depth of the ceiling frame portion may be defined or described by the ceiling frame. The ceiling frame may have an upper surface, which may be configured to support a further modular building unit stacked or seated on the modular building unit. The ceiling frame may have a lower surface , which may be seated on the support structure. The depth may be defined between the upper and lower surfaces. The ceiling frame may comprise, and/or may be formed from or defined by, a plurality of elongate frame members. The elongate frame members may define the upper and/or the lower surfaces. The ceiling frame may comprise a perimeter frame structure, which may comprise elongate beams. The perimeter frame structure may comprise first and second side beams, which may be disposed substantially parallel to one another. The perimeter frame structure may comprise first and second end beams, which may be disposed substantially parallel to one another. The first and second side beams, and the first and second end beams, may together form or define a majority or all of the perimeter frame structure. The ceiling frame may comprise at least one support beam which may extend in a direction between the first and second end beams, and disposed between the side beams. The ceiling frame may comprise a plurality of elongate joists. At least one joist may extend in a direction between the first and second side beams. At least one joist may be arranged to have a depth which is different to (e.g. less than) a depth of beams forming the perimeter frame structure.

The ceiling frame portion may comprise at least one mounting member, and may comprise a plurality of mounting members. The mounting member may serve for mounting a further (e.g. upper) modular building unit on the modular building unit. The at least one mounting member may protrude or extend from an upper surface or extent of a frame member or members forming part of the ceiling frame. The at least one mounting member may extend upwardly and/or in a generally vertical direction, optionally away from the upper surface/extent of the ceiling frame member(s). The at least one mounting member may take the form of a block, post, stub, pin or

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The at least one mounting member, in particular an upper surface of said mounting member, may be configured to contact a lower surface of a further (e.g. upper) modular building unit stacked or seated on the modular building unit, in particular a lower surface of a floor frame of said further unit. This may provide the advantage that a void, space or gap can be formed between the two modular building units using the at least one mounting member, which may accommodate e.g. utilities/building services equipment such as sewerage conduits as discussed above. Said void can be created with minimal additional structure, and so cost and weight savings. The ceiling frame portion depth may be defined between the upper surface of the mounting member(s) and a lower surface of the ceiling portion (which may be defined by the ceiling frame, in particular by lower surfaces of its elongate frame members). The at least one mounting member may be coupled to, or provided by (e.g. integral to), the ceiling frame. There may be a plurality of mounting members, which may be spaced apart around the perimeter of the modular building unit defined by the ceiling frame. A mounting member may be provided at each corner of the modular building unit, which comers may be defined by the ceiling frame. The ceiling frame portion may comprise a plurality of mounting members. An aperture may be provided between an adjacent pair of mounting members, through which utilities/building services equipment can pass. A plurality of apertures may be provided, each aperture defined between an adjacent pair of mounting members.

The ceiling frame portion may comprise, or may define, a load transfer section. The load transfer section may be configured to transfer load to the support structure. The load may be that imparted by a further (e.g. upper) modular building unit, which may be stacked or seated on the modular building unit.

The ceiling frame portion, in particular its ceiling frame, may be configured to support a planar ceiling or ceiling structure. Said planar ceiling structure may define a ceiling of the modular building unit. Said planar ceiling structure may comprise, or may be defined by, one or more planar ceiling panel. The depth of the ceiling frame portion may not include said planar ceiling structure, other structural or insulative material connected to said planar ceiling structure, and/or any decorative finish or covering (such as a cementitious coating) applied to said planar ceiling structure.

Reference is made in this document to a ceiling frame portion of the modular building unit, and to a ceiling of the unit. Reference to a ceiling frame portion (and a ceiling) should be taken to mean an upper structure which covers or encloses an internal volume of the modular building unit. It will be understood that the ceiling frame portion of the modular building unit will not typically provide a weather-resistant ceiling structure intended to prevent e.g. water ingress into the modular building unit. For example, a ceiling structure may be formed separately and positioned above the modular building unit in order to weatherproofing it. However, the modular building unit could optionally provide such a ceiling, for example by arranging the ceiling frame portion to additionally provide or define an external or outer ceiling for the unit. This may be an option particularly e.g. for single storey buildings comprising the modular building unit, or where the unit forms an uppermost storey of a building. Suitable options can include a flat ceiling structure.

The ceiling frame portion may comprise structural (e.g. elongate) frame members. The ceiling frame portion, in particular the load transfer section, may take the general form of a lattice or lattice type structure. The ceiling frame portion, in particular the load transfer section: may comprise a lower structural member, which may define a lower surface of the load transfer section; may comprise an upper structural member, which may define an upper surface of the load transfer section; and may comprise at least one connecting member, which may extend between and connect the lower structural member to the upper structural member. The at least one connecting member may serve for transferring loads from the upper structural member to the lower structural member, and so to the support structure. There may be a plurality of connecting members. At least one connecting member may take the form of a strut, which may be disposed substantially perpendicular to a main axis of the upper and/or lower structural member. At least one connecting member may take the form of a brace, which may be disposed transverse to a main axis of the upper and/or lower structural member, suitably at an angle other than 90°.

The ceiling frame portion, in particular the load transfer section, may comprise a plurality of generally elongate parts, which may together define the load transfer section. The support structure may define a plurality of walls of the modular building unit, which may be external walls (e.g. at, or defining at least part of, a perimeter of the unit). A generally elongate part may be provided for each wall. The generally elongate parts may each be seated on a respective wall. The generally elongate parts may each be disposed transverse to (optionally substantially perpendicular to) at least one adjacent generally elongate part. Each generally elongate part may comprise respective lower and upper structural members, and at least one connecting member extending between and connecting the lower and upper structural members. The upper structural members of the elongate parts may together form a perimeter frame (or loop member), which may be an upper perimeter frame. The lower structural members of the elongate parts may together form a perimeter frame (or loop member), which may be a lower perimeter frame.

The ceiling frame portion may define the services void. The services void may comprise an upper boundary, which may be defined or formed by a plane containing the upper surface of the load transfer section. The services void may comprise a lower boundary, which may be defined or formed by a plane containing the lower surface of the ceiling section. The services void may be defined between a plane containing the upper surface of the load transfer section, and a plane containing the lower surface of the ceiling section.

The services void may have, or may be of, a height (which may be a second height). The height of the void may be greater than the height of the load transfer section. The (second) height may be in the range of about 250mm to about 350mm, or greater. A (second) height in the region of about 275mm to about 295mm may be preferred.

The load transfer section may form an outer part of the ceiling frame portion. The load transfer section may define at least part of an outer perimeter of the ceiling frame portion. The load transfer section may comprise a perimeter structure, which may extend around a perimeter of the modular building unit. The ceiling section may form an inner part of the ceiling frame portion. The ceiling section may be disposed inwardly of the load transfer section in that it may be disposed within the outer perimeter. The load transfer section may define or comprise an inner perimeter. The ceiling section may be positioned within the inner perimeter. The ceiling section may extend below the load transfer section within the inner perimeter. The load transfer section, and/or the ceiling section (in particular their structural frame members) may be formed from any suitable material and construction technique, but may in particular be cold-formed (e.g. folded) metallic members, such as of a light gauge steel material (forming a light gauge steel frame or LGSF).

The circulation space may be defined wholly by the (or a) modular building unit. For example, where the circulation space provides access from the outside of the building, the space may be defined wholly by a single such unit. The circulation space may be defined in combination by a plurality of modular building units. For example, where the circulation space provides access between upper and lower living spaces, two or more units may cooperate to define the access, e.g. each may form part of a staircase or lift shaft. The at least one modular building unit may define (and suitably may completely or entirely define) at least one room, and may define a plurality of rooms. The at least one modular building unit may comprise an internal volume, and the room(s) may be defined within, and may accommodate part of, said volume. The at least one modular building unit may be arranged so that it comprises one or more wall, which may define a boundary or boundaries (optionally all boundaries) of said room. At least one room may contain a wet facility, which may be selected from the group comprising a bathroom, a shower room, an ensuite, a W/C or washroom, and a utility room. One or more further room of the plurality of rooms may be arranged to contain a wet facility.

The at least one modular building unit may be arranged to define at least part of a perimeter of the building, which may be an external perimeter. The modular building unit may comprise one or more wall, and a wall or walls of the modular building unit may be arranged to define said part of the perimeter. The wall or walls may be arranged so that an external surface of the wall or walls defines an external surface of the building, or may be clad or surfaced with an exterior surface finish/coating (e.g. panels, bricks slips, cementitious render).

According to a sixth aspect of the present invention, there is provided a modular building assembly comprising: a first modular building unit; and a second modular building unit positioned on the first modular building unit so that the second modular building unit is supported by the first modular building unit; in which the first modular building unit comprises a structural frame, the structural frame comprising: a floor frame portion configured to support a planar floor structure, the floor frame portion having a depth of up to about 70mm (2.756”); a ceiling frame portion having a depth of at least about 150mm (5.906”); and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which the modular building unit optionally defines a circulation space configured to provide at least one access function for a building comprising the modular building unit.

The first modular building unit may have any of the further features set out above in relation to the fifth aspect. The second modular building unit may be a modular building unit according to the fifth aspect, and so may have any of the further features set out above.

According to a seventh aspect of the present invention, there is provided a building comprising the modular building unit of the fifth aspect, or the modular building assembly of the sixth aspect.

The building may be a hybrid building, in particular a hybrid residential building, comprising a first building section and a second building section. The first building section may be an on-site construction at a final location for the building. The second building section may be defined by and/or may comprise the modular building unit of the fifth aspect, or the modular building assembly of the sixth aspect. The first and second building sections may be configured to be connected at the final location to form the building. The building may be a modular building comprising a plurality of modular building units (at least one of which is the modular building unit according to the fifth aspect), or at least one (and optionally a plurality) of modular building assemblies according to the sixth aspect. An internal volume of the building, optionally excepting an upper or outer roof of the building, may be formed entirely by said units/assembly or assemblies.

The building may comprise a foundation comprising a load bearing structure and thermal insulation. The modular building unit/assembly may be located on the foundation so that the load bearing structure provides structural support for the modular building unit/assembly, and so that the thermal insulation thermally insulates the modular building unit/assembly relative to the ground.

The circulation space (which may also be referred to as a circulation zone or transition space/zone) may be arranged to provide one or more access function selected from the group comprising: access between upper and lower living spaces of the first building section (e.g. between upper and lower storeys of the section, via a staircase, or a lift shaft and lift); access between a first living space and at least one further living space of the first building section, said living spaces optionally being isolated from one another within the first building section and optionally on a same level/storey of the section (e.g. via a hallway /lan ding and one or more doorway or walkway); and access into the first building section from the outside of the building, and so access into the building from its exterior (e.g. via one or more doorway or walkway, and optionally also a hallway).

The modular building unit may have any of the further features set out above in relation to the fifth aspect.

According to an eighth aspect of the present invention, there is provided a method of constructing a hybrid building comprising the steps of: constructing a first building section at a final location for the building; at a location away from the final location, constructing a modular building unit according to the fifth aspect of the invention to a substantially assembled form; transporting the modular building unit to the final location in the substantially assembled form, and arranging the modular building unit to form at least part of a second building section of the building; and connecting the first and second building sections to form the building.

The building may be a hybrid residential building.

The method may comprise constructing a foundation for the building, which may comprise providing the foundation with a load bearing structure and thermal insulation. The method may comprise locating the at least one modular building unit on the foundation so that the load bearing structure of the foundation provides structural support for the modular building unit, and so that the thermal insulation of the foundation thermally insulates the modular building unit relative to the ground. The method may comprise arranging the first building section so that it is supported by the foundation. The method may comprise arranging the modular building unit so that it forms a planar floor structure of the second building section, and may comprise providing the planar floor structure with an upper support surface. The method may comprise forming the planar floor structure by positioning a planar floor panel or panels on the floor frame portion of the modular building unit, and arranging said panel so that it forms the upper support surface.

The method may comprise providing the first building section with a floor, and may comprise providing the floor with an upper support surface. The method may comprise arranging the floor of the first building section so that its upper support surface is at a common or uniform height with the upper support surface of the modular building unit. The method may comprise providing the floor of the first building section with a depth equivalent to the depth of the floor frame portion of the modular building unit plus a depth of the planar floor structure of the modular building unit.

Further features of the method may be derived from the text set out elsewhere in this document, including in any of the other disclosed aspects, particularly in or with reference to any one or more of the fifth to seventh aspects.

Reference is also made to the hybrid building and associated construction methods disclosed in International patent publication nos. WO2022/243696, WO2022/243695, WO2022/243694, WO2022/243693 and WO2023/222853, the disclosures of which are incorporated herein by this reference.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is an isometric view of a modular building unit, and a modular building assembly comprising the modular building unit, according to an embodiment of the invention;

Figs. 2 and 3 are side and end views of the modular building unit, and the modular building assembly comprising the unit, shown in Fig. 1 , drawn to a different scale and taken in the directions of the arrows A and B respectively;

Figs. 4 and 5 are enlarged perspective views of parts of portions of a structural frame of the modular building unit;

Fig. 6 is a perspective view of a hybrid building according to an embodiment of the invention, comprising the modular building unit (and the modular building assembly) of Figs. 1 and 2, shown with an external layer of the building removed;

Fig. 7 is a perspective view of the hybrid building shown in Fig. 6, shown including its external layer; Figs. 8 and 9 are plan views of lower and upper storeys respectively of the hybrid building shown in Figs. 6 and 7, drawn to a different scale;

Fig. 10 is a simplified wire -frame isometric view of the modular building assembly of Fig. 1, shown relative to a foundation of the building of Figs. 6 and 7;

Fig. 11 is an enlarged vertical cross-sectional view of part of the foundation, and of the modular building unit, shown in Fig. 10;

Figs. 12 and 13 are plan views of floor and ceiling frame portions, respectively, of the structural frame shown in Figs. 4 and 5;

Fig. 14 is a wire -frame isometric view of a plurality of modular building assemblies, configured to form part of a building according to an alternative embodiment of the invention; and

Fig. 15 is an isometric view of a ceiling frame portion forming part of a structural frame of a modular building unit according to a further embodiment of the invention;

Fig. 16 is an enlarged view of part of the ceiling frame portion shown in Fig. 15;

Fig. 17 is a cross-sectional front view of a modular building assembly comprising first and second modular building units, the first modular building unit comprising the ceiling frame portion of Fig. 15, the modular building assembly sectioned along line A-A of Fig. 15;

Fig. 18 is an isometric view showing building services equipment mounted on a panel to be fitted in the ceiling frame portion of Fig. 15; and

Fig. 19 is a further enlarged view illustrating a variation of the ceiling assembly shown in Fig. 15.

Turning firstly to Fig. 1, there is shown an isometric view of a modular building unit according to an embodiment of the invention, the unit illustrated generally by reference numeral 10. The modular building unit 10 is shown in the drawings with certain features removed, so that a structure of the unit can be seen. The drawing also shows a modular building assembly, indicated generally by reference numeral 12, comprising the modular building unit 10 and a further modular building unit which is indicated by numeral 14. Reference is also made to Figs. 2 and 3, which are side and end views respectively of the modular building unit 10, and the modular building assembly 12, drawn to a different scale. These drawings show structural features of the wall or face of the unit 10/assembly 12 which can be seen in the viewing direction.

The modular building unit 10 comprises a structural frame, indicated generally by numeral 16. The structural frame 16 comprises a floor frame portion 18 configured to support a planar floor structure (which will be described below), a ceiling frame portion 20, and a support structure 22 extending between and connecting the floor frame portion to the ceiling frame portion. As best shown in the enlarged perspective views of Figs. 4 and 5 (showing lower 24 and upper 26 comer regions of the structural frame 16), the floor frame portion 18 has a first depth Di, whilst the ceiling frame portion 20 has a second depth D2. A ratio of the first depth Di of the floor frame portion 18 relative to the second depth D2 of the ceiling frame portion 20 may be at least about 1:3. It will be understood that the depths Di and D2 of the floor and ceiling frame portions 18 and 20 are considered or measured in a generally vertical direction. Reference may however be made to vertical heights of the floor and ceiling frame portions 18, 20 (and parts thereof).

Numerous options for forming the structural frame 16 exist. Preferred options include a metallic frame, which can be of a cold-formed metal or metal alloy (e.g. light gauge steel), a hot formed metal or metal alloy (e.g. hot rolled steel), or combinations of the two. A hot-formed metallic frame may provide a sufficiently rigid structure so that additional perimeter support posts and bracing struts can be dispensed with (or the number of posts/ struts reduced). Other options include timber-based frames. In the illustrated embodiment however, the structural frame 16 is formed from a combination of hot-formed and cold-formed steel, comprising elongate members which may be of a generally hollow box shape in cross- section, or channels having a C, L or U-shape.

Connection methods for structural components of the frame can include welding (metallic frames), bonding and mechanical fixations such as nut and bolt assemblies and rivets.

Fig. 6 will now be referred to, which is a perspective view of a hybrid building 28 according to an embodiment of the invention, comprising the modular building unit 10 (and the modular building assembly 12) of Figs. 1 and 2. The hybrid building 10 is shown in Fig. 6 with an external layer removed so that a structure of the building can be seen. Fig. 7 is a view similar to Fig. 6, but showing the external layer 30, which in this embodiment is formed from bricks or blocks.

In the illustrated embodiment, the hybrid building 28 is a house, and in particular a detached house. The principles of the invention can however apply to other types of house, including semi-detached and terraced, as well as single storey houses (bungalows). In addition, the principles of the invention can apply to other residential buildings such as flats/apartments and hotels, and indeed to non-residential buildings, e.g. industrial or commercial buildings.

The hybrid building 28 comprises a first building section 36 and a second building section 38. The first building section 36 is an on-site construction at a final location 40 for the building, and is generally L-shaped in plan view (although not restricted to that shape). Part of the first building section 36 has been removed in the drawing, to show inside the section. The second building section 38 comprises the modular building unit 10, which is generally rectangular shape in plan view. The unit 10 is constructed to a substantially assembled form away from the final location 40, for example in a dedicated factory or facility. The unit 10 is transported to the final location 40 in its substantially assembled form, and arranged to form at least part of the second building section 38. In the illustrated embodiment, the second building section 38 is effectively formed by the modular building assembly 12, and so comprises both the modular building unit 10, and the further modular building unit 14. The further unit 14 is preferably a unit according to the invention, and so has similar features to the unit 10, which share the same reference numerals with the addition of the suffix As explained in detail in International patent publication nos. WO2022/243696, WO2022/243695, WO2022/243694, WO2022/243693 and WO2023/222853, the hybrid building 28 is formed by connecting the first and second building sections 36 and 38 together at the final location 40.

As can be seen from Fig. 6, the second building section 38 fits with the generally L-shaped first building section 36 in order to form a building having a generally rectangular shape in plan view. Other shapes are of course possible. The modular building unit 10 can have any suitable dimensions, with the proviso that it will generally be required to be transported e.g. by road or rail from the factory to the final location 40. The illustrated unit 10 is around 5300 to 5400mm in length, and around 2500 to 2600mm in width, which is particularly suited to such transportation. The unit 10 is smaller than many conventional modular building units, which can facilitate transportation and handling. This can also facilitate provision of the relatively thin floor described herein, and provides material, weight and cost savings. Although the illustrated unit 10 extends only part way between the front and back of the building 28, other units according to the invention may extend the full length of the building, and so may e.g. have a greater length dimension.

The modular building unit 10 defines a circulation space configured to provide one or more access function for the hybrid building 28. This is best shown in Figs. 8 and 9, which are plan views of lower 32 and upper 34 storeys respectively of the hybrid building 28, drawn to a different scale. The circulation space is indicated by numeral 42, and shown in broken outline and cross-hatched in the drawings. In the illustrated embodiment, the circulation space 42 provides three access functions. One such function is access between lower 44 and upper 46 living spaces of the building 28, provided respectively by the lower and upper storeys 32, 34. This is achieved by means of a staircase 48 in the modular building unit 10 (but could be achieved e.g. via a lift shaft and lift). The living space 44 forms a lounge or sitting room, whilst the living space 46 forms a bedroom, and the circulation space 42 therefore provides access between these different living spaces.

Another such function is access between a first living space and at least one further living space of the building, the living spaces being isolated from one another within another part of the building. As can be seen in Fig. 8, the first building section 36 comprises the living space 44 (lounge or sitting room), and a further living space 50, which forms an open plan kitchen-dining room. The circulation space 42 provides access between these living spaces 44 and 50, by means of walkway openings 52, 54 and a hallway 55. It will be noted here that the precise configuration of walkway openings shown in Figs. 8 and 9 are slightly different to those shown in the drawing Figs. 1 to 3 of the unit 10. This illustrates alternative possible positions for the openings. The circulation space 42 additionally provides access between the lower living space 44 (and also the space 50) and the upper living space 46, which are effectively isolated from one another within the first building section 36. Also, further living spaces 56 and 58 (also bedrooms) are provided in the upper storey 34 of the first building section 36, and the circulation space 42 provides access both between these further living spaces 56 and 58, and between the lower living spaces 44/50 and these further living spaces. Another such function is access into the building 28 from an exterior 60 of the building, via a doorway or walkway 62 of the unit 10, which in this case forms a front doorway for the building. The doorway 62 opens on to the hallway 55 to provide access to the staircase 48 (for access to upper living spaces 46, 56 and 58), and the internal walkways 52 and 54 (for access to the lower living spaces 44 and 50).

Whilst the illustrated modular building unit 10 comprises a circulation space 42 which provides all three access functions described above, it will be understood that variations may provide only one or only some of the stated functions.

The provision of a modular building unit 10 having the depth relationship between its structural frame floor and ceiling portions 18 and 20 (which effectively requires that D2> 3Di) may provide particular benefits in the context of the hybrid building 28 described above. This includes facilitating matching a floor level of the second building section 38 with a floor level of the first section 36 constructed at the final location 40. In particular, the first and second building sections 36 and 38 may rest on a common foundation. This is shown in Fig. 10, which is a simplified wire -frame isometric view of the modular building assembly 12 of Fig. 1, shown relative to a foundation 64 of the building 28. The foundation 64 supports both the second building section 38 (defined by the modular building assembly 12), and the first building section 36, which has been omitted from the drawing.

It can be desirable to maintain common (or uniform) floor levels within the constructed building 28, to avoid a change in floor height between the building sections 36 and 38. Providing the modular building unit structural frame 16 with floor 18 and ceiling 20 frame portions having the stated depth relationship may have the result that the floor frame portion depth Di can be relatively shallow, so that only a small height difference need be accommodated by the first building section 36. This may provide benefits in terms of material and cost savings. In addition, arranging the floor 18 and ceiling 20 frame portions so that they have depths Di and D2 in the stated ratio may have the result that the ceiling frame portion can be relatively deep, without adversely impacting the depth of the floor frame portion. This may enable the ceiling frame portion 20 to provide a majority of the structural strength for the modular building unit 10, and space to accommodate utilities/building services equipment e.g. servicing the upper modular building unit 14, which is stacked on the (lower) unit 10. The utilities/building services equipment could include wastewater conduits for wet facilities provided in the upper modular building unit 14, water supply conduits, ventilation conduits, and electrical power and communication cables, amongst other things. The shallow floor frame portion may also help to reduce a depth D3 (Fig. 5) of structure at the intersection between the ceiling portion 20 of the (lower) modular building unit 10, and a floor portion 18' of the upper unit 14.

The ratio of the first depth Di of the structural frame floor portion 18 relative to the second depth D2 of the frame ceiling portion 20 may be up to about 1:6, and may be in a range of between about 1 :3 to about 1 :6. A ratio falling within this range may provide a good balance of a relatively thin floor portion 18, and a ceiling portion 20 that can provide a majority of the structural strength for the modular building unit 10, and/or space to accommodate required utilities/building services equipment. The ratio may however be in excess of 1 :6, and may for example be up to around 1 :7 , or up to around 1 :8.

The first depth Di of the floor frame portion 18 may be up to about 70mm (~2.756”). A floor frame portion 18 having such a depth may be relatively shallow, and may be significantly shallower than floor frame portions of conventional modular building units. Fig. 11 is referred to, which is an enlarged vertical cross-sectional view of part of the foundation, and of the modular building unit 10, shown in Fig. 10. The foundation 64 is an insulated foundation, comprising a load bearing structure 68 and thermal insulation 70. The modular building unit 10 is located on the foundation 64 so that the load bearing structure 68 provides structural support for the unit, and so that the thermal insulation 70 thermally insulates the modular unit relative to the ground 72.

As shown in Fig. 11, a level of a floor 74 of the first building section 36 may be brought up to that of the floor frame portion 18 of the modular building unit 10 (forming part of the second building section 38) by applying e.g. a cementitious screed 76 to a floor support structure of the first section, in this case the foundation load bearing structure 68. It may be preferred to restrict the first depth Di of the floor frame portion 18 to no more than around 70mm, which may be a maximum optimal height for the screed 76. However, in a particularly preferred option, the first depth Di may be up to around 50mm (~1.968”), although generally a depth in a range of about 50mm to about 70mm may be suitable.

Numerous options for forming the thermal insulation 70 exist, including constructing it from a series of shaped blocks (not shown) of a suitable insulating material which can bear the load of the completed building 10. Examples include Isoquick® insulation blocks commercially available in the UK from Build Homes Better Ltd, which can be arranged to form an insulation raft or pad. The blocks are formed from a water-resistant polymeric foam material, in particular Peripor® available from BASF SE. The blocks forming the thermal insulation 64 are typically arranged in two interlocking layers 70a/b, with interlocking features (not shown) such as protrusions and recesses provided at an interface between the layers.

The thermal insulation 70 provides a surface 78 on which the load bearing structure 68 can be positioned, and in the illustrated embodiment, provides a substantially continuous surface. The load bearing structure 68 is located on the surface 78 following positioning of the thermal insulation 70 on the ground 72. The load bearing structure 68 is insulated relative to the ground 72 by the thermal insulation 70, so that thermal energy transfer between the load bearing structure and the ground is resisted. This in turn insulates the modular building unit 10 (located on the foundation 64) relative to the ground 72, reducing/preventing thermal bridging between the unit and the ground.

The load bearing structure 68 can take the form of a layer of reinforced concrete, which can be formed at the final location 40 for the building in a conventional fashion. Moisture barrier layers (not shown) can be positioned below the thermal insulation 70, and between the upper surface 78 of the thermal insulation and a lower surface of the load bearing structure 68. The moisture barriers may take any suitable form known in the 1 field of the invention. Particularly suitable options may include: a moisture resistant sheet, which may be a substantially impermeable membrane e.g. of a polymeric material such as polyethylene.

In a variation for, the foundation 64 may be formed by positioning the load bearing structure 68 on or in the ground 72, with the thermal insulation 70 positioned on the load bearing structure and supporting the modular building unit 10 (and the first building section 36). It will be understood that the thermal insulation will then be required to have sufficient load bearing capacity to bear structural loads imparted upon it by the modular building unit 10, and indeed by a remainder of the building 28. In a further variation, the load bearing structure may be formed from pre-cast blocks or beams (not shown).

The second depth D2 of the ceiling frame portion 20 may be at least about 150mm (-5.906”), and in embodiments, may be up to about 300mm (~11.811”) , but in further embodiments could up to around 350mm, and optionally up to around 400mm. The second depth D2 may therefore be in a range of about 150mm to about 300mm, optionally up to around 400mm. A depth in the region of about 250mm to 260mm may however be preferred.

A modular building unit having such floor 18 and ceiling 20 frame portion first and second depths Di and D2 may provide a good balance of benefits, e.g. in terms of minimising disruption (during construction of the first building section 36) to accommodate the floor frame portion 18 and/or minimising a depth of structure at a transition between the lower 10 and upper 14 modular building units, whilst providing a sufficiently strong ceiling frame portion 20 and/or depth in the ceiling frame to accommodate utilities/building services equipment.

As mentioned above, the upper modular building unit 14 is a unit according to the invention. The unit 14 thus comprises a structural frame 16' having the floor frame portion 18', a ceiling frame portion 20', and a support structure 22'. The depth D3 of the structure at the intersection between the lower unit ceiling portion 20 and the upper unit floor portion 18' is typically in the range of 200mm to 300mm, bearing in mind the optional depth ranges for Di and D2 discussed above. This can be particularly beneficial in terms of material savings, and reducing complexity of a transition for the staircase 48 as it passes between the two units 10, 14. The upper unit 14 is mounted on the lower unit 10 at the final location 40, following location of the lower unit on the foundation 64.

Further details of the structure of the modular building unit 10 will now be described, with reference also to Figs. 12 and 13, which are plan views of just the floor and ceiling frame portions 18 and 20, respectively.

The floor frame portion 18 comprises a floor frame 80, which defines the first depth Di. The floor frame 80 has an upper surface 82 and a lower surface 84 (Figs. 2 and 4), and the first depth Di is defined between these upper and lower surfaces. The floor frame 80 is formed from a plurality of elongate frame members which define the upper and lower surfaces 82, 84. In the illustrated embodiment, the floor frame 80 comprises a perimeter frame structure 86, which comprises elongate beams, specifically first and second side beams 88 and 90 disposed substantially parallel to one another, and first and second end beams 92 and 94 disposed substantially parallel to one another. A first support beam 96 also extends in a direction between the first and second end beams 92 and 94, and is disposed between the side beams 88 and 90. Second and third support beams 97 and 99 are provided, the second support beam 97 extending between the side beam 88 and the first support beam 96, and the third support beam 99 extending between the first support beam 96 and the side beam 82. The support beams 96, 97 and 99 provide additional structural rigidity, and can support internal wall structures in the modular building unit 10.

The floor frame 80 also comprises a plurality of elongate joists, which extend in a direction between the first and second side beams 88 and 90. First and second sets of joists (indicated respectively by numerals 98 and 100) extend between the side beam 90 and the support beam 96. A third set of joists (indicated by numeral 102) extend between the side beam 88 and the support beam 96. Typically, the joists in the sets 98-102 are of the same depth (Di) as the beams in the perimeter frame 86, but at least some could be arranged to have a depth which is different to (e.g. less than) the depth of beams forming the perimeter frame.

The side and end beams 88-94, and the support beams 96-99, are typically of a hot-formed metallic (e.g. steel) material, suitably having a box shaped cross-section. The joists in the first and second joist sets 98 and 100 in contrast are typically of a light gauge metallic material (e.g. folded steel), which may have a U-shape in crosssection. The joists 98 and 100 support a floor structure in the modular building unit 10, and so are not required to support as high loads as for example the side and end beams 88-94, and the support beams 96-99, which as discussed above may be required to support internal walls (and optionally loads transmitted through the internal walls).

The various beams forming the floor frame 80 can be arranged to transfer loads directly to the foundation, and may be arranged so that they are line -loaded, so as to more evenly distribute such loads across the foundation (in comparison e.g. to a point-loaded structure, such as a light gauge structure. In particular, each of the side and end beams 88-94 can be arranged in contact with the load bearing structure 68 of the foundation, to more evenly transfer loading from the modular building unit 10 to the foundation. This can most suitably be achieved by constructing the floor frame of e.g. a hot-formed metallic material as described above, loading imparted on the beams being distributed more evenly along their lengths than in a point loaded structure. Thus loads not only of the modular building unit 10 itself, but loads applied to it e.g. by the upper modular building unit 14, can be transferred more evenly to the foundation load bearing structure 68. This can also apply to the support beams e.g. 96, 97 and 99, which may similarly be of a hot-formed metallic material, and arranged in contact with the load bearing structure 68 of the foundation. The support beams 96, 97 and 99 may further be arranged so that they are substantially aligned with structural features of or in the upper modular building unit 14, in particular similar support beams in a floor frame portion of the upper unit, and/or internal walls of the upper unit (which may transfer loads through the upper unit’s floor frame portion to the lower modular building unit 10). Arranging the floor frame 80 in this way may have the advantage that a material forming the thermal insulation 70 can be less dense, and/or can have a lower compressive strength. This can be beneficial because, generally speaking, insulation materials which are more dense, and/or which have a higher compressive strength, tend to be more costly. The floor frame 80 is configured to support a planar floor structure 104, which is shown in Figs. 4 and 11. The planar floor structure 104 defines a floor of the modular building unit 10, and is defined by one or more planar floor panel (one shown and given the numeral 106). Many options for forming the floor structure 104 exist, but preferred options include timber-based materials for the panel 106, such as chipboard, fibreboard and plywood. The first depth Di of the floor frame portion 18 does not include the planar floor structure 104, or indeed other structural or insulative material positioned on said floor structure, and/or any decorative floor finish or covering (such as carpet or tiles) positioned on said floor structure.

As explained above, the screed 76 forming the floor 74 of the first building section 36 typically has the same depth Di as the floor frame portion 18 (and so the frame 80). The floor 74 may be brought up to the level of that provided by the module planar floor structure 104 by positioning a further floor structure 108 on the screed floor 74. This could again be e.g. panel based and of a timber material, to provide uniformity across the building sections 36, 38. It will be understood though that various other options exist, including that the screed 74 could be arranged to have an upper surface which matches that provided by the module planar floor structure 104.

The ceiling frame portion 20 comprises a ceiling frame 110, which defines the second depth D2. The ceiling frame 110 has an upper surface 1 12 and a lower surface 114, and the second depth D2 is defined between these surfaces. The ceiling frame 110 is formed from a plurality of elongate frame members which define the upper and lower surfaces 112, 114. The ceiling frame 110 comprises a perimeter frame structure 116, which comprises first and second side beams 118 and 120 disposed substantially parallel to one another, and first and second end beams 122 and 124 disposed substantially parallel to one another. A support beam 126 also extends in a direction between the first and second end beams 122 and 124, and is disposed between the side beams 118 and 120. As for the floor support beam 96, this support beam 126 provides additional structural rigidity and can support internal wall structures in the modular building unit 10.

The ceiling frame 110 also comprises a plurality of elongate joists, which extend in a direction between the first and second side beams 1 18 and 120. First and second sets of joists (indicated respectively by numerals 128 and 130) extend between the side beam 116 and the support beam 126. Third and fourth sets of joists (indicated respectively by numerals 132 and 134) extend between the side beam 118 and the support beam 126. Typically, the joists in the sets 128-134 have a depth which is less than the depth (D2) of the beams in the perimeter frame 116, but at least some could be of the same depth.

The side and end beams 118-124, and the support beam 126, are again typically of hot-formed steel having e.g. a box shaped cross-section, whilst the joists in the first to fourth joist sets 128-134 are typically of light gauge steel having e.g. a U-shape in cross-section.

The ceiling frame portion 20 defines a load transfer section configured to transfer load to the support structure

22. The load is that imparted by the upper modular building unit 14 stacked on the lower modular building unit.

10. The ceiling frame portion 20 also comprises at least one mounting member, which serves for mounting the further (upper) modular building unit 14 on the modular building unit 10. In the illustrated embodiment, the ceiling frame portion 20 comprises a plurality of mounting members 136a-d, each positioned at comers of the ceiling frame 110. Further mounting members 136e-h are positioned along the end beams 122, 124 and side beams 118 and 120 spaced from the relevant comer mounting members. In addition, at least one mounting member can be provided on the support beam 126, Fig. 1 showing two such mounting members 136i and 136j . These provide support for portions of the upper modular building unit 14, in particular internal wall structures. The mounting members 136a-j protrude or extend from an upper surface or extent of the beams forming the ceiling frame 110, indicated at 138 in Fig. 5. The mounting members 136a-j extend in a generally vertical direction, away from the upper surface 138, and suitably take the form of a block, post, stub, pin or peg.

Upper surfaces of the mounting members 136a-j are configured to contact a lower surface of the further (upper) modular building unit 14, which is stacked or seated on the modular building unit 10 and connected to the mounting members. Referring to Fig. 5 showing the mounting member 136c, the mounting member defines the upper surface 112 discussed above, which abuts a lower surface 140 of a floor frame of said further unit (defined by its side frame member 18'). This may provide the advantage that a void, space or gap 142 is formed between the two modular building units 10 and 14, which can accommodate e.g. utilities/building services equipment, such as sewerage conduits as discussed above. The location of such conduits is shown in broken outline in Fig. 2, and indicated generally by numeral 144. These conduits 144 may connect to wet facilities in the upper modular building unit 14, which will be described below, and may ultimately pass through a service module 146 in the unit 10 to a sewer (not shown). The void 142 can be created with minimal additional structure, and so affords cost and weight savings. The second depth D2 of the ceiling frame portion 20 is defined between the upper surfaces 112 of the mounting members 136a-j and the lower surface 114 of the ceiling portion (defined by the ceiling frame 110, in particular by lower surfaces of its frame members). The mounting members 136a-j are typically coupled to, or provided by (e.g. integral to), the ceiling frame 110.

As can be seen therefore, the ceiling frame portion 20 comprises a plurality of mounting members 136a-h. At least one aperture is provided between an adjacent pair of mounting members, through which utilities/building services equipment can pass. For example, referring to Fig. 1, an aperture 145 is defined between the adjacent mounting members 136b and 136g through which utilities/building services equipment can pass, e.g. into the first building section 36 to provide utilities/services to the first building section.

The upper modular building unit 14 is connected to the lower unit 10 to form the assembly 12, in order to resist particularly lateral movement of the units relative to one another. Various options exist for connecting the units 10 and 14, including welding, bonding and mechanical fixings. Suitable mechanical fixings can include nut and bolt assemblies, pins and locating sockets and the like.

The ceiling frame portion 20, in particular its ceiling frame 110, is configured to support a planar ceiling or ceiling structure 148, which is shown in Fig 5. The planar ceiling structure 148 defines a ceiling of the modular building unit 10, and is defined by one or more planar ceiling panel (one shown and given the numeral 150). Many options for forming the ceiling structure 148 exist, but preferred options include plasterboard panels or sheets. The second depth D2 of the ceiling frame portion 20 does not include the planar ceiling structure 148, other structural or insulative material connected to said planar ceiling structure, and/or any decorative finish or covering (such as a plaster render).

Reference is made in this document to a ceiling frame portion of the modular building unit 10, and to a ceiling of the unit. Reference to a ceiling frame portion 20 (and a ceiling) should be taken to mean an upper structure which covers or encloses an internal volume of the modular building unit 10. It will be understood that the ceiling frame portion 20 of the modular building unit 10 will not typically provide a weather- resistant roof structure intended to prevent e.g. water ingress into the modular building unit. To this end, and referring to Fig. 6, a separate roof structure 150 is shown which is constructed e.g. from a plurality of roof trusses 152. The roof structure 150 bridges across the first and second building sections 36 and 38, and weatherproofs the building 28. However, the modular building unit 10 could optionally provide such a roof, for example by arranging the ceiling frame portion to additionally provide or define an external or outer roof for the unit. This may be an option particularly e.g. for single storey buildings comprising the modular building unit, or where the unit forms an uppermost storey of a building. Suitable options can include a flat roof structure.

In the light gauge steel frame (LGSF) structural frame 16 shown in the drawings, the support structure 22 is relatively complex, and will not be described in detail. In brief however, the support structure 22 comprises a plurality of support posts or columns 154a-c (Fig. 1), each provided at a comer of the frame 16, extending between and connected to the floor and ceiling frame portions 18, 20. Further support posts or columns are provided at locations on a perimeter of the floor frame portion 18 which are spaced from one or more of the corners. Numerous such further support posts are referred to, and given the numerals 154d-k.

To ease construction, the various support posts 154a-k are each connected at one end to a floor mounting member, and at a second opposite end to a ceiling mounting member, to form wall structures that can be connected to the floor and ceiling portions 18, 20. Fig. 1 shows an external face or wall 155 of the unit 10 defined by the support structure 22, which wall is provided internally in the constructed building 28. A floor mounting member 157 is mounted on the floor side beam 88, and a ceiling mounting member 159 is mounted to the ceiling side beam 1 18. The support posts 154b, 154d and 154g-k shown in the drawing are connected between the floor and ceiling mounting members 157 and 59, so that they extend between (and support) the floor and ceiling portions 18, 20 in the assembled unit 10. It will be noted that the floor mounting members in particular do not extend across parts of the unit 10 perimeter frame structure 116 which provide doorways or walkways for accessing the first building section 36. See for example at the walkway 52 providing access to the open plan room 50. This is to provide the uniform floor level between the first and second building sections 36 and 38 discussed above with reference to Fig. 11.

The support structure 22 also comprises transverse bracing or support members. A plurality of bracing members (one indicated with the numeral 156) extend between pairs of adjacent support posts/columns 154, in a direction generally perpendicular to the support posts. Diagonal bracing members (one indicated with numeral 158) extend between some of the support posts 154 and the floor or ceiling frame portions 18, 20.

Other options for the support structure 22 exist, including structural insulated panels (SIPs), and other panels e.g. of a cement-based material.

As can be seen in Figs. 8 and 9, the modular building unit 10 defines a plurality of rooms within the building 28, at least some of which provide wet facilities in the form of a W/C or washroom 160, and a utility room 162.

The unit 10 is arranged so that it comprises internal walls which define a boundary or boundaries of the washroom 160 and utility room 162. Referring for example to the washroom 160, the unit 10 includes internal walls 162 to 166 which define a space that forms the washroom. The washroom 160 is accessed from the hallway 55 of the circulation space 42, whilst the utility room is accessed directly from the open plan room 50.

In a similar fashion, the upper modular building unit 14 comprises rooms providing wet facilities in the form of a bathroom 168 which is accessed via a landing 172 of the circulation space 42, and an ensuite 170 which is accessed from the bedroom 58. As explained above, sewerage conduits 144 connecting to washing and toilet facilities in the bathroom 168 and the ensuite 170 can be accommodated at least partly in the void 142 between the units 14 and 10. This can include, for example, sewerage connections for a toilet 174, bath 176 and sink 178 in the bathroom 168.

In the illustrated building 28, the modular building units 10 and 14 are enclosed within the external brick layer 30. Walls of the units 10 and 14 are formed by connecting wall panels or sheets to the structural support frames 16 and 16’ (in particular to supports posts and bracing members). For example, and as shown in Fig. 6, panels 180-184 can form an external wall 186 of the modular unit 10. The modular building units 10, 14 can however be arranged to define at least part of a perimeter of the building, in particular an external perimeter. This can be achieved by arranging the panels 180-184 as external cladding panels.

In a variation on the illustrated embodiment, the building 28 may be a modular building comprising a plurality of modular building units which form all (or at least a majority) of an internal volume of the building. This is illustrated in Fig. 14, which is a wire -frame isometric view of a plurality of modular building assemblies, configured to form part of a building 28". Like components of the building 28" with the building 28 share the same reference numerals, with the addition of the suffix The building 28" comprises a plurality of modular building units, at least one of which is a modular building unit according to the invention. In a particularly preferred option, all of the modular building units are units according to the invention.

The modular building units are arranged in assemblies stacked as discussed above in relation to the modular building assembly 12. Thus a modular building assembly 12" comprises a lower modular building unit 10" and an upper modular building unit 14" stacked on the lower unit. A further modular building assembly 12a" similarly comprises a lower modular building unit 10a" and an upper modular building unit 14a" stacked on the lower unit. Between them, the modular building units of the assemblies 12" and 12a" define the entire internal volume of the building 28", with the exception of an upper or outer roof of the building (not shown), which may be formed at a final location for the building (as for the roof structure 150), or formed as a modular (transportable) structure.

Turning now to Fig. 15, there is shown an isometric view of a ceiling frame portion 20b according to a further embodiment of the invention. Fig. 16 is also referred to, which is an enlarged view of part of the ceiling frame portion (taken from a different angle), and Fig. 17, which is a cross-sectional front view of a modular building assembly 12b comprising first (lower) and second (upper) modular building units 10b and 14b, sectioned about line A-A in Fig. 15. The first modular building unit 10b comprises the ceiling frame portion 20b. Like components of the modular building assembly 12b (including the ceiling frame portion 20b) with the modular building assembly 12 share the same reference numerals, with the addition of the suffix ‘b’.

The ceiling frame portion 20b of this embodiment comprises a load transfer section 188, which takes the form of a lattice or lattice type structure. The load transfer section 188 comprises elongate structural frame members, comprising a lower structural member in the form of a beam 278, an upper structural member also in the form of a beam 280, and at least one connecting member, which extends between and connects the lower structural member to the upper structural member. In the illustrated embodiment, the load transfer section 188 comprises a plurality of connecting members in the form of struts 282, disposed generally perpendicular to the lower and upper structural members 278 and 280, and a plurality of transverse bracing members 284 disposed at a nonperpendicular angle relative to the lower and upper structural members 278 and 280 (suitably at an angle other than 90°, for example between perhaps 20° and about 45°).

The lower structural member 278 defines a lower surface 286 of the load transfer section 188, whilst the upper structural member 280 defines an upper surface 288. The lower and upper structural members 278 and 280, and the connecting members 282 and 284, effectively form sides of the load transfer section 188. The connecting members 282 and 284 serve for transferring loads from the upper structural member 280 to the lower structural member 278, and so to the support structure 22b of the lower modular building unit 10b (which define external walls of the modular building unit 10b).

The load transfer section 188 comprises a plurality of generally elongate parts which together define the load transfer section. In the illustrated embodiment, the load transfer section 188 has a generally quadrilateral shape in plan view (generally rectangular), comprising left and right elongate parts 290 and 292, and front and back elongate parts 294 and 296. The number of generally elongate parts generally corresponds to the number of walls provided by the support structure 22b of the modular building unit 10b, one such wall 155b being shown in Fig. 17. It will be understood that the remainder of the modular building unit 10b, including its floor frame portion and side structure, are substantially as described above in relation to Figs. 1 to 13, and will not be discussed again here.

The elongate parts 290-296 are each generally aligned with a respective wall e.g. 155b, so that they are in substantially the same plane. Each elongate part 290-296 is seated on a respective wall e.g. 155b, and arranged so that it is disposed transverse to (suitably substantially perpendicular) the adjacent elongate parts. Each of the generally elongate parts 290-296 comprises respective lower and upper structural members 278 and 280, and connecting members 282, 284. The upper structural members 280 of the elongate parts 290-296 together form an upper perimeter frame or loop member 116b of the load transfer section 188, whilst the lower structural members 278 together form a lower loop member 116b' of the load transfer section.

In this embodiment, the load transfer section 188 is configured to provide a plurality of apertures 145b through which utilities/building services equipment can pass. This is illustrated in Fig. 16, where it can be seen for example that an aperture 145b is sized so that a ventilation conduit (e.g. 220) can pass through it. This facilitates connection of building services equipment (indicated generally by numeral 190 in Fig. 15) located within a services void 142b between the stacked modular building units 10b, 14b into a first building section of a building comprising the modular building assembly 12b (e.g. first building section 36 of building 28), as well as into the lower and upper modular building units themselves (and/or items/equipment contained within them). The building services equipment 190 will not be described in further detail, but can comprise any of the options discussed herein. The building services equipment 190 can thus be accommodated within the services void 142b, and connected through the apertures 145b, without requiring that the equipment pass generally downwardly into the lower modular building unit 10b, or generally upwardly into the upper modular building unit 14b stacked or seated on the lower unit (save where it is specifically desired to supply building services into/through the lower unit, or into/through the upper unit).

The apertures 145b are defined by or between structural members of the ceiling frame portion, in particular its load bearing section 188, specifically between at least some of the lower and upper structural members 278, 280 and the connecting members 282, 284. Referring for example to the aperture 145b labelled in Fig. 16, the aperture is defined between and/or bordered by the upper beam 280, the transverse bracing member 284, and the strut 282. A further aperture, labelled 145b' for the purpose of this discussion, is defined between and/or bordered by the lower beam 278, another transverse bracing member 284, and another strut 282. A series of the apertures 145b are defined around a perimeter of the ceiling frame portion 20b, as can be seen particularly in Fig. 15.

The lower surface 286 defined by the load transfer section 188 is seated on upper surfaces 298 of the support structure 22b (particularly walls e.g. 155b defined by the support structure), as best shown in Fig. 17. The load transfer section 188 also comprises an upper surface 300, which supports the upper modular building unit 14b, specifically a floor frame portion 18b' of the upper unit. The load transfer section 188 is of a first height (or depth) Hi, which is defined between the upper and lower surfaces 300, 286, and which is typically in the range of about 200mm to about 300mm. A height Hi in the region of about 250mm to 260mm may be preferred.

As discussed above, a floor frame portion (not shown) of the modular building unit 10b corresponds to the floor frame portion 18 of unit 10, and so is of a hot-formed metallic material having the same depth range Di described above, i.e. typically in the range of about 50mm to about 70mm. The height Hi of the load transfer section 188 may define or describe the depth D2 of the ceiling frame portion 20b in this embodiment. The depth ranges, and ratio of floor to ceiling frame portion depths, therefore fall within the scope of the depths and ranges set out above for the embodiment of Figs. 1 to 13.

The ceiling frame portion 20b also comprises a ceiling section 302, which is configured to define or support a ceiling 304 of the modular building unit 10b. In this embodiment, the ceiling section 302 comprises a lower surface 306 which supports a series of generally planar ceiling components in the form of ceiling panels (one shown in Fig. 17 and given the numeral 308), which are configured to form the ceiling 304. The panels 308 are connected to the ceiling section 302, arranged below the lower surface 306.

The lower surface 306 of the ceiling section 302 is provided lowermost of the ceiling section, and defines a lower extent of the ceiling section. The ceiling section 302 effectively comprises a plurality of lower surface portions which together make up the lower surface. In the illustrated embodiment, the ceiling section 302 comprises a plurality of resilient mounting bars by which the ceiling 304 is mounted to the ceiling section. Fig. 17 shows one such resilient mounting bar 310, which comprises a lower surface defining a lower surface portion 312 that, together with other such mounting bars (not shown), form the lower surface 306. The resilient mounting bars 310 are of a type known in the industry, and have a generally corrugated mounting part defining the lower surface portion 312, which provides a sound absorption/deadening function to reduce transmission of vibrations (and so sound) through the ceiling 304 between the stacked modular building units 10b, 14b.

The ceiling section 302 is disposed inwardly of the load transfer section 188 and is connected to it. The ceiling section lower surface 306 is disposed at a position that is lower than the upper surface 298 of the support structure 22b (e.g. walls 155b), as can be seen in Fig. 17. The ceiling assembly 302 effectively defines the services void 142b, the void comprising an upper boundary which is defined or formed by a plane 314 containing the upper surface 300 of the load transfer section 188, and a lower boundary which is defined or formed by a plane 316 containing the lower surface 306 of the ceiling section 302. The services void 142b has a second height (or depth) H2 which is greater than the height Hi of the load transfer section 188. The second height H2 is typically in the range of about 250mm to about 350mm. A second height H2 in the region of about 275mm to about 295mm may be preferred.

The ceiling section 302 comprises an upper surface 318 which is disposed at a position that is lower than the upper surface 300 of the load transfer section 188. The ceiling section 302 is of a third height (or depth) H3 which is defined between the upper and lower surfaces 318, 306 of the ceiling section. The height H3 of the ceiling section 302 is less than both the first and second heights Hi and H2, and may be in the range of about 70mm to about 100mm. A third height H3 in the region of about 75mm to about 95mm may be preferred. Where the ceiling section 302 itself defines the ceiling 308, the lower surface 306 which defines a boundary of the service void 142b may be formed by an upper face of the ceiling. A maximum height (or depth) H4 of the apertures 145b is dictated by structural features of the ceiling assembly 20b (including the heights Hi H2 and H3), and dimensions of structural members 278-284, but may be in the region of about 120mm to about 175mm, with a dimension of perhaps 150mm to 160mm being preferred. Of course, the structural members forming the apertures include the transverse bracing members 284. These bracing members 284 extend between the upper and lower structural members 280 and 278 at the angle shown in the drawings, and so do limit the height of the aperture towards their ends adjacent the upper structural members. An aperture 145b having such a maximum height H4 may however be sufficient to accommodate most or all different types of services (e.g. pipes or conduits) likely to be positioned in the space 142b.

The ceiling section 302 depends from the load transfer section 188, so that the ceiling section overlaps a top part of the support structure 22b (e.g. walls 155b) defining the upper surface 298, the top part taking the form of a top frame member or beam 319 of the support structure/wall. The load transfer section 188 forms an outer part of the ceiling assembly, defining an outer perimeter 320 of the ceiling assembly 20b. The load transfer section 188 effectively comprises a perimeter structure, which is defined by the various elongate parts 290-296 forming its lattice frame, and which may extend around a perimeter of the modular building unit 10b. The ceiling section 302 forms an inner part of the ceiling frame portion 20b, and is disposed inwardly of the load transfer section 188, within its outer perimeter 320. The load transfer section 188 also defines an inner perimeter 322, and the ceiling section 302 is positioned within the inner perimeter. The ceiling section 302 extends below the load transfer section 188 within the inner perimeter 322.

The ceiling section 302 also comprises a perimeter structure 324 (Fig. 16), which defines an outer perimeter 326 of the ceiling section. The perimeter structure 324 is connected to the load transfer section 188, in particular to lower structural members 278 of some of its generally elongate parts 290-296. The load transfer section 188 additionally comprises a plurality of bracing parts extending between opposed pairs of the generally elongate portions, three such bracing parts 328, 330 and 332 shown. The bracing parts 328-332 are of similar construction to the elongate portions 290-296, and will not be described here. The perimeter structure 324 can be connected to one of more of these bracing parts 328-332, and in the illustrated embodiment is connected to the bracing part 328. The ceiling section perimeter structure 324 takes the form of a structural frame, and may comprise structural (e.g. elongate) frame members 334 (Fig. 17) defining the frame, and having the resilient bars 310 defining the lower surface 306 coupled to them (although could alternatively themselves form the lower surface).

In the illustrated embodiment, the ceiling section 302 comprises a plurality of subsections which together form the ceiling section. These are shown in Fig. 15 and given the numerals 336, 338, 340 and 342. Each subsection 336-342 forms a portion of the ceiling section 302, and has its own perimeter structure as described above. The ceiling subsections 336-342 can each be independently or separately connected to the load transfer section 188 during construction of the ceiling assembly 20b. The load transfer section 188 defines separate zones or spaces, each configured to receive one of the ceiling subsections 336-342. These zones are defined by or between two or more of the elongate parts 290-296, and one or more of the bracing parts 328-332. Referring for example to the subsection 336, a zone 344 is defined by the side parts 290 and 292, the end part 294 and the bracing part 328.

One or more of the subsections 336-342 can include building services equipment 190, and the building services equipment of each such subsection may suitably be mounted on a respective board or panel shaped to fit within the services void 142b within the respective zone, e.g. zone 344. Referring to Fig. 18 for example, there is shown building services equipment 190 mounted on a panel 192. The services shown include portions of main air inlet and exhaust pipes 216, 218; air supply 220 and extract ducts 222, 224; hot and cold water pipes 252, 254; data cable 345; and electrical power cable 347. The panel 192 can be mounted in the ceiling section 302 carrying the various services 190, or can be mounted in the ceiling section prior to connection of the services. This can be before or after connection of the ceiling section 302 to the load transfer section 188.

A top panel 194 is provided overlaying the building services equipment 190. Fig. 18 is an exploded view prior to the bottom panel 192 and the top panel 194 (which provides an upper platform within the ceiling frame portion) being brought together and optionally sealed together to form a building services cartridge or module 196. Side portions 198 (which may take the form of walls that can be partial and/or comprise apertures through which services can pass) are shown and extend between the top and bottom panels 194, 192. The building services cartridge or module 196 may be permanently or releasably coupled to the structural portions of the ceiling assembly 20b either during off site module manufacture, or at the time of stacking up the modular building assembly 12b.

Where there are a plurality of ceiling subsections 336-342, the subsections may be configured to cooperate for the provision/routing of services within the void 142b (each subsection defining part of the void). As shown in Fig. 18, each subsection may contain/support a part or parts of the service equipment 190 which requires to be connected to a further part or parts contained/supported by another subsection. For example, the ventilation supply and extract ducts 216 and 218 pass along a length of the ceiling frame portion 20b through the subsections 338 and 336. The ducts may be connected up following positioning of the building services equipment within the subsections (either in cartridge/module form, or separately as discussed above). This may involve the use of connectors at junctions or intersections between portions of the services provided in each subsection. See for example connector 343 which serves for connecting portions of the extract duct 216 provided in the subsections 340 and 338. It will be understood that each ceiling subsection 336-342 may comprise or accommodate respective panels 192, 194 (and so service cartridges).

In a variation which is illustrated in the further enlarged view of the ceiling assembly 20b shown in Fig. 19, at least one aperture 145b" can be provided without the transverse bracing member 284, so that the aperture is defined between (or bordered by) the upper structural member 280, an adjacent pair of the struts 282, and the lower structural member 278. This may provide a larger aperture, having the maximum height H4 along its entire width, between the adjacent struts 222. This can be of use e.g. where the aperture is required to accommodate larger service equipment such as the ventilation supply pipes 220, 222.

Fig. 17 additionally shows part of the first building section 201 connected to the modular building assembly lb, specifically one of a plurality of joists 346 which extend between at least one side of the modular building unit/assembly and a wall of the first building section to support an upper floor 348 of the first building section. Acoustic and/or thermal insulation is provided, including in the walls 155b (and load transfer section 188) and walls 155b' of the upper unit 14b, and in the void 142b, as indicated at 353 and 355 in Fig. 17. It will be understood that the insulation 353, where provided, will be fitted around any services, and may be dispensed with depending on factors including the number and dimensions of services passing through the aperture(s) 145b. The maximum height H4 of the aperture 145b is of course less than the height H2 of the space 142b. The aperture 145b may be partially occluded by the insulation 355, although again the insulation 355 may be dispensed with, or a height of the insulation in the region of the aperture (through which services pass) may be reduced.

The floor frame portion 18b' of the upper modular building unit 14b may also be of a hot-formed metallic material, as discussed above, and may have a height (or depth) H5 in a range of about 50mm to about 70mm, with around 50mm being a preferred option. A total height of the load transfer section 9b and the floor assembly 18b' may be a sum of the heights H2 and H5. This may define the depth D3 of the structure at the intersection between the ceiling assembly 20b of the lower modular building unit 10b and the floor assembly 105b of the upper modular building unit 14b, may be between approximately 300 mm and approximately 500 mm, optionally between approximately 300 mm and approximately 400 mm, and optionally approximately 350 mm. A depth in the range of between approximately 250mm to 370mm may be preferred.

It will be understood that, during normal use, the load transfer section 188, the support structure 22b (in particular walls e.g. 155b) and the floor frame portion (corresponding to floor frame portion 18 in Fig. 1) of the lower modular building unit 10b are in the load path for loading transferred from the upper modular building unit 14b to the lower modular building unit. The ceiling section 302 is not on or in the load path, in that it is disposed inwardly of the load transfer section 188 and the support structure 22b.

For the purposes of the present invention, the depth relationship between Di and D2 may be determined based on the structure that is in or on such a load path. Accordingly, in this embodiment, Di may be based on the height of the floor frame portion (e.g. floor frame portion 18 in Fig. 1), whilst D2 may be based on the height Hi of the load transfer section 188, these being the relevant structure on the load path.

Construction options for the ceiling frame portion 20b, in particular the load transfer section 188 and the ceiling section 302, can comprise any of the options discussed elsewhere in this document. Construction options can therefore include cold-formed (e.g. folded) metallic members, such as of a light gauge steel material (forming a light gauge steel frame or LGSF).

Various modifications may be made to the foregoing without departing from the spirit or scope of the present invention.

Further aspects and/or embodiments of the invention may combine the features of one or more aspect and/or embodiment disclosed in this document. Accordingly, such further aspects and/or embodiments may comprise one or more feature selected from one or more aspect or embodiment of the invention disclosed in this document. Unless explicitly implied by context or stated in the document, the features of any method or process disclosed in this document need not necessarily be performed in the precise order set out in the relevant text and/or drawings. Accordingly, any method or process disclosed in this document may be capable of being performed in an order other than that specifically set out in the relevant text/drawings, if circumstances permit.

Features disclosed in this document (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Accordingly, features disclosed in this document may represent only one example of a generic series of equivalent or similar features.

Claims

1. A modular building unit comprising a structural frame, the structural frame comprising: a floor frame portion having a first depth, the floor frame portion configured to support a planar floor structure; a ceiling frame portion having a second depth; and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which a ratio of the first depth of the floor frame portion relative to the second depth of the ceiling frame portion is at least about 1 :3; and in which the modular building unit defines a circulation space configured to provide at least one access function for a building comprising the modular building unit.

2. A modular building unit as claimed in claim 1 , in which the ratio of the first depth relative to the second depth is up to about 1:6.

3. A modular building unit as claimed in either of claims 1 or 2, in which the first depth of the floor frame portion is up to around 70mm (-2.756”).

4. A modular building unit as claimed in either of claims 1 or 2, in which the first depth of the floor frame portion is up to around 50mm (-1.968”).

5. A modular building unit as claimed in any preceding claim, in which the second depth of the ceiling frame portion is at least about 150mm (-5.906”).

6. A modular building unit as claimed in any preceding claim, in which the second depth of the ceiling frame portion is up to about 300mm (-11.811”).

7. A modular building unit as claimed in any preceding claim, in which: the first depth is defined by a part or parts of the floor frame portion that are in a load path for loading transmitted from the ceiling frame portion through the support structure to the floor frame portion; and the second depth is defined by a part or parts of the ceiling frame portion that are in the load path.

8. A modular building unit as claimed in any preceding claim, in which the floor frame portion comprises a floor frame, and in which the floor frame has an upper surface and a lower surface, the first depth being defined between the upper and lower surfaces.

9. A modular building unit as claimed in claim 8, in which the floor frame comprises a perimeter frame structure comprising elongate beams of the first depth.

10. A modular building unit as claimed in any preceding claim, further comprising the planar floor structure, in which the planar floor structure defines a floor of the modular building unit, and in which the first depth of the floor frame portion does not include the planar floor structure.

11. A modular building unit as claimed in any preceding claim, in which the ceiling frame portion comprises a ceiling frame, and in which the ceiling frame has an upper surface and a lower surface, the second depth being defined between the upper and lower surfaces.

12. A modular building unit as claimed in claim 11 , comprising a plurality of mounting members which serve for mounting a further modular building unit on the modular building unit, the mounting members protruding from an upper surface of a frame member or members forming at least part of the ceiling frame, and in which upper surfaces of the mounting members are configured to contact a lower surface of the further modular building unit to form a void between the modular building units.

13. A modular building unit as claimed in claim 12, in which the second depth is defined between the upper surfaces of the mounting members and a lower surface of the ceiling frame member or members.

14. A modular building unit as claimed in any one of claims 1 to 10, in which the ceiling frame portion comprises or takes the form of a lattice structure.

15. A modular building unit as claimed in claim 14, in which the ceiling frame portion comprises a load transfer section, the load transfer section comprising: a lower structural member defining a lower surface of the load transfer section, the lower surface seated on an upper surface of the support structure; an upper structural member defining an upper surface of the load transfer section, the upper surface configured to support a further modular building unit; and at least one connecting member which extends between and connects the lower structural member to the upper structural member, for transferring loads from the upper structural member to the lower structural member, and so to the support structure.

16. A modular building unit as claimed in claim 15, in which the ceiling frame portion comprises a ceiling section configured to define or support a ceiling of the modular building unit, the ceiling section disposed inwardly of the load transfer section and connected to it.

17. A modular building unit as claimed in claim 16, in which the ceiling section comprises a lower surface disposed at a position that is lower than the upper surface of the support structure.

18. A modular building unit as claimed in any preceding claim, in which said access function is selected from the group comprising: access between upper and lower living spaces of the building; access between a first living space and at least one further living space of the building, said living spaces being isolated from one another within another part of the building; and access into the building from its exterior.

19. A modular building unit as claimed in any preceding claim, in which the modular building unit defines at least one room, and comprises one or more wall which forms boundaries of said room.

20. A modular building unit as claimed in claim 19, in which at least one room contains a wet facility, said room selected from the group comprising a bathroom, a shower room, an ensuite, a W/C or washroom, and a utility room.

21. A modular building assembly comprising: a first modular building unit; and a second modular building unit positioned on the first modular building unit so that the second modular building unit is supported by the first modular building unit; in which the first modular building unit comprises a structural frame, the structural frame comprising: a floor frame portion having a first depth, the floor frame portion configured to support a planar floor structure; a ceiling frame portion having a second depth; and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which a ratio of the first depth of the floor frame portion relative to the second depth of the ceiling frame portion is at least about 1 :3; and in which the modular building unit defines a circulation space configured to provide at least one access function for a building comprising the modular building unit.

22. A modular building assembly as claimed in claim 21, in which the first modular building unit is a modular building unit according to any one of claims 1 to 20.

23. A modular building assembly as claimed in claim 22, in which the second modular building unit is a modular building unit according to any one of claims 1 to 22.

24. A building comprising the modular building unit of any one of claims 1 to 20, or the modular building assembly of any one of claims 21 to 23.

25. A building as claimed in claim 24, in which the building is a hybrid residential building comprising a first building section and a second building section, and in which: the first building section is an on-site construction at a final location for the building; the second building section comprises the modular building unit; and the first and second building sections are connected at the final location to form the building.

26. A building as claimed in claim 24, in which the building is a hybrid residential building comprising a first building section and a second building section, and in which: the first building section is an on-site construction at a final location for the building; the second building section is defined by the modular building assembly; and the first and second building sections are connected at the final location to form the building.

27. A building comprising a plurality of modular building units, at least one of the modular building units being a modular building unit according to any one of claims 1 to 20, in which an internal volume of the building is formed substantially entirely by the plurality of modular building units.

28. A building as claimed in any one of claims 24 to 27, comprising a foundation comprising a load bearing structure and thermal insulation, in which the modular building unit is located on the foundation so that the load bearing structure provides structural support for the modular building unit, and so that the thermal insulation thermally insulates the modular building unit relative to the ground.

29. A building as claimed in any one of claims 24 to 28, in which the circulation space is arranged to provide one or more access function selected from the group comprising: access between upper and lower living spaces of the first building section; access between a first living space and at least one further living space of the first building section, said living spaces being isolated from one another within the first building section; and access into the first building section from the outside of the building.

30. A method of constructing a hybrid building comprising the steps of: constructing a first building section at a final location for the building; at a location away from the final location, constructing a modular building unit according to any one of claims 1 to 20 to a substantially assembled form; transporting the modular building unit to the final location in the substantially assembled form, and arranging the modular building unit to form at least part of a second building section of the building; and connecting the first and second building sections to form the building.

31. A method as claimed in claim 30, comprising: constructing a foundation for the building, including providing the foundation with a load bearing structure and thermal insulation; locating the modular building unit on the foundation so that the load bearing structure of the foundation provides structural support for the modular building unit, and so that the thermal insulation of the foundation thermally insulates the modular building unit relative to the ground; and arranging the first building section so that it is supported by the foundation.

32. A method as claimed in either of claims 30 or 31 , comprising: arranging the modular building unit so that it forms a planar floor structure of the second building section, including providing the planar floor structure with an upper support surface; providing the first building section with a floor, including providing the floor with an upper support surface; and arranging the floor of the first building section so that its upper support surface is at a uniform height with the upper support surface of the modular building unit.

33. A method as claimed in claim 32, comprising providing the floor of the first building section with a depth equivalent to the first depth of the modular building unit plus a depth of the planar floor structure of the modular building unit.

34. A modular building unit comprising a structural frame, the structural frame comprising: a floor frame portion configured to support a planar floor structure, the floor frame portion having a depth of up to about 70mm (2.756”); a ceiling frame portion having a depth of at least about 150mm (5.906”); and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which the modular building unit defines a circulation space configured to provide at least one access function for a building comprising the modular building unit.

35. A modular building unit as claimed in claim 34, in which the depth of the floor frame portion is up to around 50mm (-1.968”).

36. A modular building unit as claimed in any preceding claim, in which the depth of the ceiling frame portion is up to about 300mm (-11.811”).

37. A modular building unit as claimed in any one of claims 34 to 36, in which: the depth of the floor frame portion is defined by a part or parts of the floor frame portion that are in a load path for loading transmitted from the ceiling frame portion through the support structure to the floor frame portion; and the depth of the ceiling frame portion is defined by a part or parts of the ceiling frame portion that are in the load path.

38. A modular building unit as claimed in any preceding claim, in which the floor frame portion comprises a floor frame, and in which the floor frame has an upper surface and a lower surface, the depth of the floor frame portion being defined between the upper and lower surfaces.

39. A modular building unit as claimed in claim 38, in which the floor frame comprises a perimeter frame structure comprising elongate beams of the depth of the floor frame portion.

40. A modular building unit as claimed in either of claims 38 or 39, in which the floor frame is defined by a plurality of elongate frame members which define the upper and lower surfaces.

41. A modular building unit as claimed in any one of claims 34 to 40, further comprising the planar floor structure, in which the planar floor structure defines a floor of the modular building unit, and in which the depth of the floor frame portion does not include the planar floor structure.

42. A modular building unit as claimed in any one of claims 34 to 41, in which the ceiling frame portion comprises a ceiling frame, and in which the ceiling frame has an upper surface and a lower surface, the depth of the ceiling frame portion being defined between the upper and lower surfaces.

43. A modular building unit as claimed in claim 42, comprising a plurality of mounting members which serve for mounting a further modular building unit on the modular building unit, the mounting members protruding from an upper surface of a frame member or members forming at least part of the ceiling frame, and in which upper surfaces of the mounting members are configured to contact a lower surface of the further modular building unit to form a void between the modular building units.

44. A modular building unit as claimed in claim 43, in which the depth of the ceiling frame portion is defined between the upper surfaces of the mounting members and a lower surface of the ceiling frame member or members.

45. A modular building unit as claimed in any one of claims 34 to 41, in which the ceiling frame portion comprises or takes the form of a lattice structure.

46. A modular building unit as claimed in claim 45, in which the ceiling frame portion comprises a load transfer section, the load transfer section comprising: a lower structural member defining a lower surface of the load transfer section, the lower surface seated on an upper surface of the support structure; an upper structural member defining an upper surface of the load transfer section, the upper surface configured to support a further modular building unit; and at least one connecting member which extends between and connects the lower structural member to the upper structural member, for transferring loads from the upper structural member to the lower structural member, and so to the support structure.

47. A modular building unit as claimed in claim 46, in which the ceiling frame portion comprises a ceiling section configured to define or support a ceiling of the modular building unit, the ceiling section disposed inwardly of the load transfer section and connected to it.

48. A modular building unit as claimed in claim 47, in which the ceiling section comprises a lower surface disposed at a position that is lower than the upper surface of the support structure.

49. A modular building unit as claimed in any one of claims 34 to 48, in which said access function is selected from the group comprising: access between upper and lower living spaces of the building; access between a first living space and at least one further living space of the building, said living spaces being isolated from one another within another part of the building; and access into the building from its exterior.

50. A modular building unit as claimed in any one of claims 34 to 49, in which the modular building unit defines at least one room, and comprises one or more wall which forms boundaries of said room.

51. A modular building unit as claimed in claim 50, in which at least one room contains a wet facility, said room selected from the group comprising a bathroom, a shower room, an ensuite, a W/C or washroom, and a utility room.

52. A modular building assembly comprising: a first modular building unit; and a second modular building unit positioned on the first modular building unit so that the second modular building unit is supported by the first modular building unit; in which the first modular building unit comprises a structural frame, the structural frame comprising: a floor frame portion configured to support a planar floor structure, the floor frame portion having a depth of up to about 70mm (2.756”); a ceiling frame portion having a depth of at least about 150mm (5.906”); and a support structure extending between and connecting the floor frame portion to the ceiling frame portion; in which the modular building unit defines a circulation space configured to provide at least one access function for a building comprising the modular building unit.

53. A modular building assembly as claimed in claim 52, in which the first modular building unit is a modular building unit according to any one of claims 34 to 51.

54. A modular building assembly as claimed in claim 52, in which the second modular building unit is a modular building unit according to any one of claims 34 to 51.

55. A building comprising the modular building unit of any one of claims 34 to 51 , or the modular building assembly of any one of claims 52 to 54.

56. A building as claimed in claim 55, in which the building is a hybrid residential building comprising a first building section and a second building section, and in which: the first building section is an on-site construction at a final location for the building; the second building section comprises the modular building unit; and the first and second building sections are connected at the final location to form the building.

57. A building as claimed in claim 55, in which the building is a hybrid residential building comprising a first building section and a second building section, and in which: the first building section is an on-site construction at a final location for the building; the second building section is defined by the modular building assembly; and the first and second building sections are connected at the final location to form the building.

58. A building comprising a plurality of modular building units, at least one of the modular building units being a modular building unit according to any one of claims 34 to 51, in which an internal volume of the building is formed substantially entirely by said units.

59. A building as claimed in any one of claims 55 to 58, comprising a foundation comprising a load bearing structure and thermal insulation, in which the modular building unit is located on the foundation so that the load bearing structure provides structural support for the modular building unit, and so that the thermal insulation thermally insulates the modular building unit relative to the ground.

60. A building as claimed in any one of claims 55 to 59, in which the circulation space is arranged to provide one or more access function selected from the group comprising: access between upper and lower living spaces of the first building section; access between a first living space and at least one further living space of the first building section, said living spaces being isolated from one another within the first building section; and access into the first building section from the outside of the building.

61. A method of constructing a hybrid building comprising the steps of: constructing a first building section at a final location for the building; at a location away from the final location, constructing a modular building unit according to any one of claims 34 to 5 Ito a substantially assembled form; transporting the modular building unit to the final location in the substantially assembled form, and arranging the modular building unit to form at least part of a second building section of the building; and connecting the first and second building sections to form the building.

62. A method as claimed in claim 61, comprising: constructing a foundation for the building, including providing the foundation with a load bearing structure and thermal insulation; locating the at least one modular building unit on the foundation so that the load bearing structure of the foundation provides structural support for the modular building unit, and so that the thermal insulation of the foundation thermally insulates the modular building unit relative to the ground; and arranging the first building section so that it is supported by the foundation.

63. A method as claimed in either of claims 61 or 62, comprising: arranging the modular building unit so that it forms a planar floor structure of the second building section, including providing the planar floor structure with an upper support surface; providing the first building section with a floor, including providing the floor with an upper support surface; arranging the floor of the first building section so that its upper support surface is at a uniform height with the upper support surface of the modular building unit.

64. A method as claimed in claim 63, comprising providing the floor of the first building section with a depth equivalent to the depth of the modular building unit floor frame portion plus a depth of the planar floor structure of the modular building unit.