Modular Building Systems

" Pradhan Mantri Awas Yojana " , a noble mission to construct 20 million affordable housing units by the government is an ambitious scheme with challenges. The government is all set to spend a minimum of one lakh rupees on each housing unit. This fund will be used to rehabilitate and thereby improve living conditions of Indian slums by providing affordable housing. The various challenges faced include replacing slums with low-cost sustainable construction with structural integrity that can withstand Indian subtropical conditions. This paper is a review of literature available on the construction and design of Low-Cost Modular Housing (LCMH). The main objective of the study is to provide the information to the industry with an option of using low-cost housing that can effectively provide an alternative to conventional housing construction and help into improve the living condition of people in Indian slums.

"This work presents a project developed during a 3-week Product Design Workshop, at VIA University College, Horsens, Denmark, by a group of 6 students from Faculty of Engineering, University of Porto, with Pedro Joel Costa as project manager (ALANIZ et al., 2011). This project titled “Auto-Sustainable Guest-House for VIA students” consists on an auto-sustainable compact housing solution, that presents a point of optimal balance between three major needs: space, economy and sustainability, with regard to the environment. Within this research, the following issues were addressed: Materials that adapt to the climate (auto-sustainability); Possibilities of saving resources; The basic contemporary needs of the users of temporary accommodation; The house’s dimensions that allows a minimal cost; and The territory occupation impact. According to the objective list to achieve, the “Nigel Morph” method was employed in order to collect the different hypotheses available and to select (according to the inputs) the best solutions, leading to a more precise idea about the Danish reality and sustainable concerns for construction systems in this context."

Within this work, life cycle assessment modeling is used to determine top design priorities and quantitatively inform sustainable design decision-making for a prefabricated modular building.  A case-study life-cycle assessment was performed for a 5,000 ft2 prefabricated commercial building constructed in San Francisco, California, and scenario analysis was run examining the life cycle environmental impacts of various energy and material design substitutions, and a structural design change.  Results show that even for a highly energy-efficient modular building, the top design priority is still minimizing operational energy impacts, since this strongly dominates the building life cycle's environmental impacts.  However, as an energy-efficient building approaches net zero energy, manufacturing-phase impacts are dominant, and a new set of design priorities emerges.  Transportation and end-of-life disposal impacts were of low to negligible importance in both cases.

ABSTRACT Ecological payback time was calculated for demolishing an existing commercial building with average energy performance and replacing it with an energy-efficient, prefabricated building. A life-cycle assessment was performed for a 5,000 ft2 commercial building designed by Project Frog and prefabricated in San Francisco, California, and compared to the impacts of annual energy consumption and continued status quo operation of a comparable average commercial building. Scenarios were run both with and without rooftop solar panels intended to make the prefabricated building net zero energy. The analysis considers the materials and manufacturing, transportation, annual energy use of the new building, and disposal of the existing building, compared to continued annual energy use of the existing building. The carbon payback of a new building with no solar against operation of an existing commercial building was found to be roughly eleven years, and a building with enough rooftop solar to be net zero energy was roughly 6.5 years. The full EcoIndicator99 environmental impact payback for a new efficient building with no solar was found to be twenty years, and a solar net-zero building was roughly eleven years against operation of an existing commercial building.

Within this work, life cycle assessment modeling is used to determine top design priorities and quantitatively inform sustainable design decision-making for a prefabricated modular building. A case-study life-cycle assessment was performed for a 5,000 ft2 prefabricated commercial building constructed in San Francisco, California, and scenario analysis was run examining the life cycle environmental impacts of various energy and material design substitutions, and a structural design change. Results show that even for a highly energy-efficient modular building, the top design priority is still minimizing operational energy impacts, since this strongly dominates the building life cycle's environmental impacts. However, as an energy-efficient building approaches net zero energy, manufacturing-phase impacts are dominant, and a new set of design priorities emerges. Transportation and end-of-life disposal impacts were of low to negligible importance in both cases.