Most of us have trouble understanding how much energy we use in our homes—a lack of information makes it difficult for any of us to know. As homeowners and renters, we may understand how much our energy costs each year, but we don't necessarily know how much energy we are actually using or if that energy use is better or worse than other similar homes.
We can tell you how efficiently your home is operating by analyzing your home's energy use and benchmarking it to models that take into consideration the age and size of the home, the climate, and the number of people living in the home. This benchmarking results in a simple score between 0 and 100, with 100 being reserved for the most efficient of homes. Two operational energy (OPEN) ratings are provided, one for site energy (the energy consumed at the building) and another for the carbon emissions associated with that energy use.
An OPEN (operational energy) rating demonstrates how efficiently a home is operating by comparing its energy consumption to that of other similar homes. It's a relative comparison that accounts for key building characteristics and occupancy—we expect larger homes and homes with many occupants to use more energy. Our goal is to help people understand how efficiently their homes are operating and reduce energy consumption.
Although our comparisons are relative to similar homes, our research shows that homes with higher OPEN ratings use less energy on average. Not only are these homes using energy more efficiently than predicted, they are using less energy overall. We can see this graphically below, where we've plotted OPEN ratings and annual energy consumption (in kBTU) for over 12,000 single family homes. In general, homes with the highest ratings are using the least amount of energy.