Living in a condo building also reduces energy bills with better insulation. Units are surrounded by other units that are also temperature controlled, which helps to maintain the temperature of all the units. Studies show that, from 1970 to 2009, large apartment and condo buildings showed the greatest improvement in terms of energy consumption by household. Newer apartment and condo buildings are especially energy efficient, even though they tend to have more appliances that use energy, such as dishwashers and air conditioners. But because those appliances are more likely to be energy efficient, and because of other advances in technology and construction, residents don’t have to sacrifice sustainability for any of those conveniences.