More than 90% of our time is spent in buildings i.e. either in the office or at home. Energy used in buildings (residential and commercial) accounts for a significant percentage of a country’s total energy consumption. This percentage depends greatly on the degree of electrification, the level of urbanization, the amount of building area per capita, the prevailing climate, as well as national and local policies to promote efficiency. In many countries, buildings consume more energy than transport and industry. The International Energy Agency (IEA) statistics estimate that globally, the building sector is responsible for more electricity consumption than any other sector, 42%. The building sector encompasses a diverse set of end use activities, which have different energy use implications. Energy efficiency measures for buildings are approaches through which the energy consumption of a building can be reduced while maintaining or improving the level of comfort in the building. These measures can typically be categorized into:
Heating and Cooling: Heating and cooling systems use more energy than any other systems in our homes. Typically, over half of the energy of an average family’s energy bills is used to keep homes at a comfortable temperature. You can save energy and money by installing insulation, maintaining and upgrading the equipment, and practicing energy efficient behaviors. A seven to ten degree adjustment to your thermostat setting (lower in winter, higher in summer) for just eight hours per day can lower heating and cooling bills by 10%. Programmable thermostats can automatically control temperature for time of day and season.
Insulation and Weatherization: You can reduce heating and cooling needs by investing in insulation and weatherization products. Warm air leaking into your home in summer and out of your home in winter can waste a lot of energy. Insulation wraps your house in a nice warm blanket, but air can still leak in or out through small cracks. Often the effect of small leaks is the same as keeping a door wide open. One of the easiest moneysaving measures you can do is caulk, seal, and weather-strip all the cracks to the outside. You can save 10% or more on your energy bill by stopping the air leaks in your home.
Doors and Windows: About one-quarter of a typical home’s heat loss occurs through the doors and windows. Energy efficient doors are insulated and seal tightly to prevent air from leaking through or around them. If your doors are in good shape and you don’t want to replace them, make sure they seal tightly and have door sweeps at the bottom to prevent air leaks. Installing insulated storm doors provides an additional barrier to leaking air. Most homes have many more windows than doors. Replacing older windows with new energy efficient ones can reduce air leaks and utility bills. The best windows are constructed of two or more pieces of glass separated by a gas that does not conduct heat well.
Landscaping: Although it isn’t possible to control the weather, landscaping can reduce its impact on home energy use. By placing trees, shrubs, and other landscaping to block the wind and provide shade, people can reduce the energy needed to keep their homes comfortable during heating and cooling seasons.
Electricity and Appliances: Appliances that contribute the most to a typical household’s energy use are refrigerators, clothes washers, and dryers. When shopping for new appliances, you should think of two price tags. The first one is the purchase price. The second price tag is the cost of operating the appliance during its lifetime. You’ll be paying that second price tag on your utility bill every month for the next 10 to 20 years, depending on the appliance. Many energy efficient appliances cost more to buy, but save money in lower energy costs. Over the life of an appliance, an energy efficient model is always a better deal.
Lighting: Halogen, or energy-saving incandescent bulbs, are more expensive than incandescent bulbs, but use 25% less energy and last three times as long. Compact fluorescent light bulbs (CFLs) provide the same amount of light as incandescent bulbs. CFLs can cost more to buy, but they save money in the long run because they use only one-quarter the energy of incandescent bulbs and last 10 times longer. Light emitting diodes (LEDs) are even more efficient than CFL bulbs and last longer, too. For now, they are still the most expensive lighting choice, but expect to see costs come down as more LED bulbs are produced.
Water Heating: Water heating is the second largest energy expense in your home. It typically accounts for about 18% of your utility bill. Heated water is used for showers, baths, laundry, dishwashing, and general cleaning. There are four main ways to cut your water heating bills: Use less hot water, turn down the thermostat on your water heater, insulate your water heater and pipes, and buy a new, more efficient water heater. Other ways to conserve hot water include taking showers instead of baths, taking shorter showers, fixing leaks in faucets and pipes, and using the lowest temperature settings on clothes washers.