Thermally Comfortable Affordable Housing: A Study on Residential Building Code In India

Abstract

On an average, India has more than 3000 Cooling Degree Days (CDD). The multifamily public housing being constructed under India’s Prime Minister Awas Yojana (PMAY) is aimed at providing formal housing to the society’s Economic Weaker Section (EWS). It is essential that this housing delivers thermally comfortable in-doors to the occupants. This study mapped the design and construction practices followed under PMAY Urban (PMAY-U) against India’s Residential Energy Building Code, Eco Niwas Samhita (ENS). The metric prescribed in ENS is Residential Envelope Transmittance Value (RETV). For 80 PMAY-U projects, information related to spatial design, and walling assemblies was collated. 30 projects were short-listed for detailed analysis. The RETV for selected projects was calculated. The analysis demonstrated that walling assemblies and technologies having a lower thermal transmittance value (U-value) resulted in meeting the ENS prescribed RETV numbers, hence, code compliance. The study further extended to assess the energy performance of the housing unit by exploring the change in walling assemblies. The change in thermally comfortable hours were reported in the range of 4145 and 6034, and Energy Performance Index (EPI) of the dwelling units were reported between 64 and 68 kWh/m²/year for the various walling assemblies.