Imagine being able to buy a home the same way you would when buying a car or a major household appliance â€" by knowing how much it’s going to cost you to run. Consumers can examine MPG stickers for cars and Energy Guide labels for appliances to get a good idea about how energy efficient they are. But what can homebuyers look at to assess the energy performance â€" and affordability of the homes they are viewing? They can ask for the HERS Index Score.