Optimizing Building Envelope Configuration for Social Housing Projects in India

In India, the social housing sector is a significant contributor to the rising demand for construction materials, labor, and energy. As energy demand rises, it becomes more important to improve and optimize the energy performance of new and existing buildings, while maintaining affordability for lower-income groups. This study compares and contrasts social housing projects proposed under the Rajiv Awas Yojana and implemented under the Pradhan Mantri Awas Yojana-Urban, in 5 cities across different climatic zones in India, namely Allahabad, Barkot, Byatarayanapura, Kota, and Rourkela. The structures under consideration had similar unit carpet areas ranging between 25 and 30 sq. m as per government recommendation and have comparable building layouts and wall assembly. The study includes an analysis of detached and apartment-style building units, i.e., single-family unit for Barkot, multi-family duplex unit for Byatarayanapura, and multi-family apartment-style units for Allahabad, Kota, and Rourkela. The methodology included a manual computation of the Window-Wall ratio and Window-Floor Ratio of these projects and a comparison with the recommended values as per the Eco-Samhita Niwas, 2018. Further analysis was done using OpenStudio simulations to identify the preferable orientations and wall assembly options given the climatic zones. Primary findings from the simulation of the different building components noted a 0.5–7.2% energy savings in dwellings when properly designed and optimized. On the contrary, it was also observed that improper orientation or construction sets increased the energy demands by 0.5–3% in the given buildings. The study indicates that the “one size fits all” approach currently prevalent in the construction of social housing projects needs reconsideration.