Homes can be energy-efficient in two ways. They can be energy-efficient in the way they are used and the way they are built.
Making your home more energy-efficient, simply by using it in an energy-efficient manner, is simple and inexpensive; it requires no energy audit or expensive energy upgrades.
Using your home in an energy-efficient manner consists of turning off lighting when nobody is in the room, cooking outside during summer, and unplugging appliances when they are not in use. During the summer months, keeping windows closed and shades down during the heat of the day is a very cost-effective way to reduce energy use. This may seem too obvious to some, but many opportunities to save energy in this manner are squandered by most people.
In summary, homes can become far more energy-efficient, simply by changing occupant behavior. Homeowners can adopt many practices around their home that will save a lot of energy—turning off lights when not in use and closing windows in the heat of the day during the summer—as well as teach these practices to their children. All of this is done without purchasing any energy efficiency upgrades to their house or incurring any first costs.