The housing sector is the second largest energy consumer in India with 95 percent of the urban population lying in the middle and lower income categories. Considering this demand for affordable housing, there is a strong potential for energy saving in the affordable housing sector. The given study delineates the gap in past research in creating comprehensive sustainable rating systems for energy efficient interventions in buildings and analyses the trade-offs in energy gains, economic cost and thermal comfort due to walling material substitution in warm-humid climate for an affordable housing unit.