According to the Sindh Health Department, more than 1,200 people succumbed to the heat wave that gripped the city last month. With power outages adding to the intense heat , the National Energy Conversation Centre (ENERCON), which is responsible for formulating guidelines for energy conversation in Pakistan, is emphasising strict adherence to thermal-efficient buildings codes for all new commercial and residential projects. Doing so will result in the reduction of interior temperatures and , consequently, energy bills, by nearly 40%.
ENERCON’S building guidelines include:
* Cellings. The use of fall cellings which ventilated air gaps will insulate and houses and lower temperatures considerably. Another way to do so is to construct buildings with high ceilings – ranging between 12 and 15 feet.
* Rooftops. Instead of using commercial concrete (the industry practice), roofs should be paved with insulated and reflective materials such as stabilized mud, fired clay with extruded hollow tiles, or polystyrene with plain concrete. This will ensure minimal solar heating and heat transfer and reduce indoor temperatures considerably.
* Windows. Single-glazed windows are inadequate to keep building interiors cool when temperatures soar beyond 40 degrees Celsius. Double-glazing is recommended as it reduces internal temperatures by two to three degree Celsius.
* Walls. Constructing porous walls, which allow maximum ventilation internally, should become the norm , rather than using concrete. Furthermore, use lighter shades of paint for the exterior walls (and roofs) to increase sun reflectivity , and reduce heat absorption.
* Gaps between boundary walls and one – and two -storey buildings. Most building bylaws state that the minimum distance between the external boundary wall and a one – and two -storey building until should be 1.7 metres. However, this gap is insufficient to create a winter venturi – which allows wind to flow through the building at high speeds and lower the building’s temperature – therefore the distance should be at least two metres.
By Ibrahim Murad. The writer is a consultant engineer.