Q–We are in the process of seeking a newly-built home. What are some of the things we should consider from an energy-efficiency standpoint?
We wouldn’t mind spending a little extra money up front to save money over the years as we are planning to stay in our next home for at least 20 years or so.
via e-mail
A–There’s much for you to consider, whether you’re buying a new home that’s already been built and is ready to move into, or whether you’re going to have a home built to your specifications, according to John Katrakis of J.T. Katrakis & Associates, an energy and environmental consulting and management firm in Barrington.
First, however, you should realize that you’ll probably need to be a bit aggressive with the builder in asserting your wants and needs, says Katrakis. “There aren’t too many builders who tout the energy efficiency of their homes.”
Start by asking a builder if he knows what the energy costs of a new home will be, suggests Katrakis. For example, if built with the proper amount of insulation (R-40 in the attic and around R-20 in the walls), it shouldn’t cost more than $400 a year to heat a home that’s about 2,300 square feet.
“And see if the builder can guarantee those heating cost, as some builders do,” Katrakis says.
Another sign that a new home’s energy efficient is if the builder substitutes 2-by-6-inch walls for the industry standard 2-by-4-inch walls. This substitution allows for a deeper wall cavity and more insulation inside the wall–an R-18 value versus an R-13.
“And this option shouldn’t cost you a whole lot more as the bigger studs can be placed farther apart than 2-by-4-inch studs, which saves money on wood,” says Katrakis.
Ideally, the insulation in those wall cavities should be loose-fill cellulose instead of blankets or batts, says Katrakis. “The loose fill has a tighter, more compact fill in the walls and will work better.”
Next, visually inspect the house to see how “tight” it is, says Katrakis. “Make sure that any gaps or plumbing chases are well-sealed to minimize unnecessary air flow.”
If you can visit a home during the construction phase, make sure the foundation walls below grade are covered with a moisture-proof, rigid insulation board that’s 1 to 2 inches thick, says Katrakis.
The windows should have double panes with argon gas between them to minimize heat transfer through the glass between inside and outside the home.The window panes should have at least a low emissivity (low-E) coating, a film on the glass that helps prevent heat loss on cold days by slowing down the transfer of warmth to the ouside. This coating admits light but at the same time filters out heat from the sun.
Also, check for the R-value of the window, says Katrakis. “Any good window manufacturer will specify the total R-value of a window,” he says. “Settle for nothing less than R-4.”
If you’re building a house, try to have the builder orient it on the lot so that the longer side of the dwelling faces south. “That would maximize the solar gain of the house during the cold weather months,” says Katrakis. “Meanwhile, the side of the house facing west should be the shortest side of the house to minimize solar gain in the summer and also minimize (exposure to) the northwest winds in the cold weather months.”
You also will want a maximum number of windows on the south side of the house to bring in natural light, but a minimum number on the north side to prevent cold winter winds from infiltrating the house.
There’s more. Next week we’ll talk about what you can do with room layouts, whole-house fans, heating and cooling plants and landscaping to maximize a new home’s energy efficiency.
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Got a question about home energy or home environmental issues? Write to Energy Q&A, Chicago Tribune, Your Place section, 435 N. Michigan Ave., 4th Floor, Chicago, Ill. 60611. Or you can e-mail energy qa@aol.com. Questions will be answered only through the column.
