Sir: Fossil fuels are depleting fast and their use is creating climate warming. Buildings consume about 50 percent of the total primary energy in Pakistan, and reduction in this energy can go a long way to overcome energy shortages and reduce the pace of climate change. The Net Zero Energy Home (NZEH) concept is a new one and involves reduction in the energy use of buildings for heating, cooling, lighting, equipment, ventilation, domestic hot water, etc, with passive strategies such as the use of insulation, day lighting, natural ventilation, efficient equipment, solar collectors, window to wall ratio, orientation of building, ground heat exchanger, etc. After reducing the energy needs of the building, the balance of energy is provided by a renewable energy source such as photovoltaic (PV) or wind. As the NZEH is connected to the grid, if it produces more energy than required it exports to the grid, and when it needs more energy than the PV/wind is able to provide, it imports from the grid. The size of PV is such that the net yearly energy balance is zero. IMRAN IQBAL Islamabad