It's a question real estate agents hear all the time - so, what have the utility bills been like on this house? So common, in fact, that both buyer's agents and listing agents will often have that information in hand before a prospective buyer even asks - especially if it shows the house in a good light.
But what does this data really tell us? Most likely, all it tells us is how much energy the previous family used. What we don't know is how. Do they like to crank up the heat in the winter? Freeze the house in summer? Leave TVs on all night? Perhaps they are miserly. What if they live in one room of the house and wear 5 layers of clothing for cold days?
Other factors might also mislead us into believing the home is more energy efficient than it really is. For example, they may have low bills but travel extensively or used the house on a limited basis in the past year.
How do you determine what the energy use is really like?
I would not completely dismiss the data from these old bills, but factor them into your overall evaluation. What's more likely is they can serve as a red flag. If you find out that the current owners had a $700 heating bill in the winter (not unheard of in a large, older home), then that should alert you to the potential that the house has little to no insulation and an inefficient heating source.
Most people don't take a close look at the mechanical systems and structural items when they are shopping for homes, they are focused on whether the house feels right. Ideally though, you want to take a closer look during that 2nd visit and during inspections. I personally try to point out some especially good or bad things I notice as I'm showing clients a home.
Home inspectors will generally hit the biggies - age of the heating and air conditioning, insulation level and ventilation in the attic, and operating condition of windows and doors are among some of the issues they may point out. The primary goal of the home inspector, however, is to determine whether these are operating adequately - not whether they are efficient for the home.
There are also some easy things you can look for yourself. Check for energy labels on equipment and appliances. If it has a basement, is there any insulation along external walls or in the joists? Do windows, doors, and pipes have good caulking and weatherstripping? Each of these can give you an idea of where improvements may be needed. The Department of Energy EnergySavers website discusses these issues in greater depth.
Factoring energy use into your housing decision
You may have come across a great old house, charm by the bucket loads, and then find out that their utility bills were sky high. Should that scare you off? It shouldn't if everything else about the house is what you are looking for. Consider it in what you plan to pay and do to the house before you move in. You don't want to end up getting a house "on the cheap," and then find out the money you thought you saved is lost paying the utility company.
This is where an energy audit can pay for itself - at least with an older home in need of some updates. An auditor will go through the home and prepare a detailed analysis of the energy usage and what cost-effective improvements can be made. My personal preference would be for buyers to take this step during their inspection period so that they can make a more fully informed decision about the home before purchase, but my opinion on this issue is a bit of an exception among real estate agents - a discussion I leave for another day.