If you think you can cover the water heater but you can't do this for safety purposes. Use insulation jacket for keeping your water heater warm and it will not allow the outside air to enter in the tank. You can use thermostat for measuring the energy consumption. If water consumption is less, heat your water at 120 degrees Fahrenheit otherwise heat your water at 140 degrees Fahrenheit. If you are not at home, and you want to turn on your heating or cooling device just few minutes before you reach home, set the timer with specific temperature you want. Timer will automatically start the device at specific temperature and time. It is blessing of science that bestowed us. Remote Control heating system is there if you forget to set thermostat before leaving home. On the other hand, government is constantly telling the public that the search for other energy sources may not be economical too. At times, the cost of one type of unconventional energy source is just not reasonable enough to be surveyed by the government. There is also the difficulty of transition from the usual energy sources to the unconventional one. Resistance of walls is measured through R-value, which is very high in passive houses. The indoor environment will always be moderate because of the bricks that act like shield against intense weather conditions. All rooms have standardized temperature unlike the uneven temperatures in ordinary houses. The reason behind is that building materials notably affect the cost of cooling as well as heating. You can easily maintain a comfy temperature level in your house just by selecting materials wisely. Design of house is another thing to be considered. You can hire an architect having good experience of designing buildings with significant energy efficiency. You have no need to turn on these solar energy bulbs manually. If there is a light then these bulbs are turn off automatically. The use of solar energy bulb is very easy. Just purchase the solar energy bulb from the market, installed it on your required place and use it. You have no need to worry about long procedures as you need in electrical bulb installation.