Many existing houses could be more energy efficient. Adding better insulation, using alternative fuel sources, or creating smarter exposure to natural light will all add to efficiency. But these structural changes can be expensive. But there are options. The following tips will ensure that energy savings are possible without spending more money. HEATING 1. Lower your thermostat by one degree C and save 240 kg (529 lb) of CO2 per year. If you feel cold, put on another layer. A cooler temperature is healthier and makes you more active. 2. Turn the heat right down at night. Use warm beds…