When Radhika and Uday Shankar returned from the US with their daughter, they needed extra space in the 40-year-old house they shared with their parents in Karpagam Gardens. Architect Anupama Mohanram, who runs Green Evolution, figured the best idea was to build a two bedroom and bath extension on the terrace, but she wanted to avoid overloading the original structure.
The new design stayed well within the FSI and setback rules and yet added 600 sq. ft to the old house. Mohanram created a lightweight structure using a hollow steel frame of columns and beams that supported a tile profile metal roofing finish. The framework was in-filled with insulating hollow clay blocks to form the walls. A gypsum board false ceiling on two inches of rigid insulation gives a neat interior finish. The sloping roof / ceiling not only adds interest to the space but also helps funnel the breeze. In Chennai, the biggest problem of building on the roof is the heat. Mohanram has created rigid insulation to ensure the roof stays cool through the hot months. In fact, the family has actually avoided air-conditioning this first summer of their stay.
To maximise natural light and cross-ventilation, breeze directions and sun paths were studied before locating and orienting window openings. For example, there are no windows on the west façade to avoid the high afternoon radiation. In addition, there are high ceilings and wall slits set high to expel warm air while an exterior wall envelope in-fill of hollow clay blocks keeps rooms relatively cool even during peak summers.
Athangudi tiles revive a traditional and sustainable art form while adding a splash of colour. An innovative two-level loft made of bamboo provides a hideaway for children. Wardrobes, shelves and insect screens are made of salvaged wood from container boxes and curtain rods of bamboo. Besides this, the home has unplastered exterior walls to minimise cement and uses LED lights. All grey water is collected in a separate tank at the ground level and reused for gardening.