India Collaboration

International Cooperative Research: Investigation of Lightweight Materials and Constructability Techniques in Cost-Effective Housing in India and the USA

The housing industry is a vitally important economic engine and satisfies the basic human need for shelter of the citizenry, both in India and the United States. The employment base and GDP contribution of this industry is extremely significant in both nations. Despite differences in economic stature, the need for safe, durable, and affordable housing in both countries is acute. According to a Confederation of Indian Industries’ (CII) estimate, the current housing supply-to-demand ratio in India stands at a dismal 1:3 with an official estimate of the housing shortage at a staggering 22.9 million dwelling units. Of course, the housing shortfall in the USA is less, but by all estimates there is a critical need to develop means by which to build better homes at lower cost. The importance of housing to the US economy is perhaps best exemplified by the fact that the housing stock is the largest single asset of the U.S. and by the creation of the Partnership for Advancing Technology in Housing (PATH) by Presidential order in 1998.

Housing research that is meaningful and intellectually vigorous is conducted in both the US and India, of course. In point of fact, the proposed research team has conducted such research. The simple perspective of the proposed research is that both nations will benefit from a rich, intellectual exchange of the results and approaches to housing research. Specifically, the proposed research will combine the talent and ideas of researchers from Arizona State University (ASU), San Diego State University (SDSU), and the Indian Institute of Technology Madras (IITM) to complete a detailed review of the potential for autoclaved aerated concrete (AAC) and other similar materials which will become a major component of the production housing industry in India and the US. For social, economic, and historical reasons, the popular home building material in the United States has been wood. In contrast, the Indian industry has relied primarily on brick and concrete. There are well-documented advantages and disadvantages to both systems. However, the energy and thermal mass properties, durability, and cost effectiveness of AAC seem to have potential advantages over both of these systems. In this research, consideration of AAC research previously conducted at each of the universities involved will be expanded by discussion and integration with the work done at the other universities. Manufacturability and constructability and their implications for production system design in residential construction have been extensively studied by the US representatives. The Indian representatives have extensive material characterization experience with AAC. These strengths will be combined in order to synergistically expand the understanding of AAC in residential production in both settings.

Research will include detailed descriptive research on AAC use in the field in both Indian and American construction contexts. This evaluation will be used to calibrate simulation models previously developed at ASU to simulate aspects of wood framing production on an AAC system. With the resulting calibrated model, what-if analyses can be conducted to provide guidance to homebuilders on the most cost-effective and efficient production methods for both nations. This process represents an extension of the ASU method of working from the structural system and up through the component systems until the whole house can be modeled. This systemic perspective will require creative solutions to the problem of avoiding trade conflicts; it is impractical to suggest that the whole trade contractor base re-train to develop methods for routing building services through the revised structure on their own. Finally, combination of the knowledge and material strength and durability test results (primarily at IITM) will allow the development of design aids to overcome code and designer unwillingness issues.

The broader impact of the proposed research begins with the creation of a technical linkage between ASU, SDSU, and IITM on a vital issue, namely housing, crossing international boundaries. Researchers and students with different views, backgrounds, and experiences will learn from each other. Hopefully the collaboration will grow through additional funding from charitable foundations and other international funding sources. An important added potential is the prospect that this research could lead to the identification of housing technologies that can be exported across international boundaries. The research team plans to incorporate the findings of the research projects in respective graduate and undergraduate courses as well.