House hunting? Consider home’s energy costs

March 30, 2008

There are so many homes on the market that I think it’s a good time to buy. What do I need to consider when looking at a home’s energy efficiency?

Congratulations for considering energy efficiency when purchasing a home. Most home buyers are so interested in the granite countertops and sunken tubs, they overlook a home’s ongoing expenses. A house really comes with two price tags — the purchase price and the cost to operate it, such as ongoing maintenance, property taxes and energy costs.

We can’t help you with maintenance issues or property taxes, but we can offer some tips on what to look for when considering a house’s energy costs.

House size and age

We often get phone calls from customers who’ve finally built their dream McMansion on a little piece of paradise in the country and are shocked when they see the energy costs for their 3,800-plus-square-foot abode. They can’t understand why this house could use so much more energy than their previous, more modestly sized home. All things being equal, larger houses consume more energy than smaller ones. If you need a larger home or simply want one, be prepared to pay more to operate it.

Very old houses, or even homes built in the 1960s and 1970s, typically use more energy per square foot than newer homes. They may have little or no insulation and leaky single-pane windows. Charming architectural details can mean more heat loss. They’re also more difficult to weatherize without jeopardizing the character of the house. So if you are buying an old house for its character, just figure that higher energy costs are part of its charm. That is unless you want to invest the time and money to make it more efficient with new windows, air sealing and insulation.

Heating, cooling systems

Space conditioning is usually the largest user of energy in a home, so consider how old the heating and/or cooling system is. Age doesn’t affect efficiencies in electric furnaces, but does make a difference in gas, oil and propane furnaces. Look to see if the furnace carries a label stating its efficiency rating — 80 percent for example. Very old furnaces won’t have a label and can be even less efficient. Newer models are 90 percent efficient or even higher.

Repair and maintenance costs may be a consideration with any older furnace, regardless of the fuel source.

Older heat pumps too will be less efficient than newer models. It would be good to know how old the heat pump is, given a pump’s average life expectancy is about 15 years.
Regardless of the type of the forced air system in the house, the duct work should be well sealed with mastic, not duct tape. Be sure to check ducts in a crawl space.

Insulation

Check the attic for insulation. It is something that can be easily added later, but at least you’ll be aware of what you’re facing. Insulation will prevent conditioned air (either heated or cooled) from being lost through the roof. It is not uncommon that insulation will “settle” over time and more will need to be added.

You’ll also want to check for floor insulation. It’s been required for most homes built in the past 25 years or so, but you may not find it in many older homes. Adding floor insulation isn’t difficult.

Wall insulation may not be present in some older homes, but can usually be added.

Water heating, appliances

Water heating is typically the second-highest energy user in a home, so check on the age of the water heater. Newer models are better insulated and more efficient than older models.
Kitchen appliances may or may not come with the house. Be aware that older refrigerators can be real energy hogs and if possible, should be replaced by one that is Energy Star rated.