Home Pay off Energy Adviser: Adding insulation to older homes can pay off

Energy Adviser: Adding insulation to older homes can pay off


Owning an old house is a bit like owning an old vehicle. Although it doesn’t have the features or comforts of its modern counterparts, the right upgrades can make it perform better than it did the day it was built.

Additionally, Clark Public Utilities can help make the investment more affordable.

Older homes are not as energy efficient as those built after 1990. Stricter building codes, along with changes in building science and materials technology mean that newer homes stay at the desired temperature longer while consuming less energy than older homes.

The difference is mainly in the insulation.

Newer homes are framed with two-by-six studs spaced 16 inches on center, while most pre-1990 homes were built with two-by-four studs 12 inches on center. Thicker walls mean more room for insulation. Fewer poles means less thermal bridging for heat to get where it’s not supposed to be.

Not only were homes built with less room for insulation, but builders often didn’t prioritize its installation. As any professional renovator can probably tell you, old attics, floors and walls can all be insulated, but to different degrees from house to house.

Homes built before the 70s may have little or no insulation in the walls or floor, but a decent layer in the attic.

Fortunately, inadequate insulation is fairly easy to remedy and offers one of the best investments for return value of any home improvement project.

With a little hard work and a few simple tools, a DIY homeowner can insulate the attic or floor in an afternoon or two. Although the do-it-yourselfer can save money on installation, it’s often worth considering at least the services of a professional. Contractors often have better insulation solutions than a do-it-yourselfer can achieve, handle all safety aspects of the project, and can provide crucial air sealing services as part of their offerings.

“Air leaks are constantly working against the heating or cooling system, and older homes are full of them,” said DuWayne Dunham, energy services supervisor. “Many contractors offer both air sealing and insulation, together they will really improve the energy performance of a home.”

Even if they are well insulated, older houses tend to heat up quickly in the summer, often because the attic is poorly ventilated. A good insulation contractor will consider ventilation and modern standards as part of a job.

“People often say the heat rises, when in reality it’s warm air rising, the heat expands and moves in any direction to heat cooler spaces,” Dunham said. . “So on a hot summer day, when an attic can easily reach over 160 degrees, that heat is going to sink into the cooler living spaces – unless it is properly vented to the outside.”

Wall insulation is generally too technical for most do-it-yourselfers. But, for an insulation contractor, it’s just another day of work. They reinforce a wall’s insulation by removing a bit of the exterior sheathing, cutting or drilling a small hole in the wall, and then blowing in the insulation until the wall is well compacted. Other companies use specially formulated spray foam insulation, which is more effective but also more expensive.

Older homes also run the risk of having asbestos in the insulation. Although not threatening if left alone, asbestos can be very harmful to human health if disturbed. Its removal should only be carried out by a professional.

After meeting certain conditions, Clark Public Utilities customers who own an electrically heated home can receive a rebate of $0.40, $0.50 and $1.20 per square foot on the attic, floor and wall insulation, respectively. It’s between 10% and 20% off a job.

Contact us at 360-992-3355 [email protected] to discuss insulation projects and to learn more about discounts.

Energy Adviser is written by Clark Public Utilities. Send your questions to [email protected] or to Energy Adviser, c/o Clark Public Utilities, PO Box 8900, Vancouver, WA 98668.