Weatherizing an Older Home

So, you finally have that classic house in town or on five acres in the country. It offers the character, classic architecture, high ceilings, lots of natural light, and that wonderful sense of space that you always wanted. And unless it was properly weatherized by the previous owner, it probably offers enormous power bills too. There are a number of measures you can take to make you dream home a safer, more comfortable, and more energy efficient place to live without spending an enormous amount of money.

If your home is an historic structure, it is important to maintain its historic integrity. In most cases, radical or irreversible changes might save a little on your monthly power bill but will cost you dearly when it comes time to sell. Your state’s historic preservation division as well as the National Park Service has good information about preserving your home’s historic integrity. I have found the park service’s web site to be particularly useful.

First a word about safety. Before you start, have the wiring in your home inspected by a licensed electrician. Older, obsolete wiring can create a fire hazard. Arc fault circuit interrupters (ACFIs) are now required by building codes in most areas, particularly on bedroom circuits. Unfortunately, older homes have fuse boxes or older breaker panels that are not compatible with ACFIs. It may be necessary to replace the fuse box or breaker panel but you will sleep better at night if you do. It will be money well spent.

Aluminum wiring is a particularly dangerous potential fire hazard. If an addition was made to your home between 1965 and 1974, it may have aluminum wiring. Talk to a qualified licensed electrician about replacing the aluminum wiring or other measures that you can take to make the home safer.

Next, your older home was most likely designed for maximum comfort before the advent of air conditioning. Be aware of these features, take advantage of them whenever possible, and don’t make any “improvements” that will compromise their effectiveness. Porches, awnings, and eaves as well as high ceilings, large strategically placed windows and shady mature landscaping all help make your home a more comfortable place to live.

Before starting any energy-saving work on your home, invest in an energy audit. The audit will tell you which improvements will be most cost effective and give you the biggest “bang for the buck.” Your power company is a good place to start. Many power companies offer rebates, discounts, and even free home energy audits to their customers. At the least, you power company can recommend qualified and reputable auditors. Your auditor should have training from the Building Performance Institute (BPI) or in the home energy rating system (HERS). A HERS rating will also qualify you for an Energy Efficiency Mortgage (EEM) that can help pay for any necessary improvements. BPI analysts and HERS raters have all sorts of technical training and skills to help identify those areas where a home is wasting energy.

Generally, the best place to start weatherizing is by limiting the air infiltration of your home’s building envelope. That’s a fancy way of saying make your home less drafty. Most older homes tend to be drafty. Use silicone caulk to seal gaps and cracks around doors and windows, and plumbing and electrical entry points. For larger openings, expanding spray foam works wonders. Don’t forget to apply weatherstripping to the windows and doors.

Remember that your fireplaces were designed to create an updraft. An enormous amount of conditioned air escapes up your chimney whether your fireplace is in use or not, so be sure your flue damper is closed when the fireplace is not in use. Dampers are not designed to be airtight so you might want to consider installing a chimney balloon, too.

Moving into the attic, it is the easiest and most cost effective place to add insulation. But the effectiveness of the insulation will be largely compromised is the attic is not air-sealed first.

Remember that air-flow and heat-flow are two different things. Imagine a cold, calm, clear winter day. You’re outside wearing your fleece jacket and it is doing a great job conserving your body heat and keeping you warm. Your fleece jacket is great insulation. Now imagine the wind starts blowing. The cold air goes through your fleece jacket, displaces the air warmed by your body heat and suddenly you’re freezing. The fleece jacket did a great job conserving heat but wasn’t effective at all when the wind started blowing. Now put on a windbreaker – warm and comfortable again. The windbreaker is equivalent to air sealing. By itself, it does little to keep you warm. But couple it with the fleece jacket and you have a very effective combination.

The same thing applies to your attic. You will be wasting most of your money and get minimal results if you insulate your attic without first air sealing. So, start by checking for air leaks. If you have existing insulation in your attic, you’ll have to temporarily move it out of the way. As you’re crawling into your attic, check your attic hatch or access stairway to be sure that it is well sealed (weather-stripped) and be sure that it is insulated. Hvac supply store near me