Here we are once again, in the middle of winter in Michigan. And if you happen to live in an older house, built at least 50 years ago, I can assume that your outside walls and rooms are already cold. That’s the nature of an older house: for all of their charm and beauty, only 20 percent of homes built before 1980 are well insulated, according to Energy Saving for the Novice, published by EnergyBright in 2010. In today’s world of energy efficiency and the “green movement”, this may seem odd and perhaps even cruel, but honestly, back in earlier days it made a lot of sense.
Unlike modern-built homes that are often wrapped in a synthetic water-resistant membrane and pumped full of insulation, older homes were designed to breathe. Before we had technology to control moisture and vapor flow in a house, builders knew that allowing air to move through wall and ceiling cavities could control excess moisture and therefore could protect materials from deterioration and rot. This concept has worked relatively well since the 19th century. The main concern with this system, of course, involves indoor comfort levels when the outside air dips below acceptable temperatures.
The bottom line is that insulating older buildings can be a good thing, if done properly. Before you respond to those TV commercials selling you on all the benefits of insulating your cold and drafty house, here are some tips that you may want to consider:
- Don’t treat an old house like a new house. They were built differently and sometimes react differently to air and moisture problems. Modern products and systems don’t always work properly in older buildings.
- Seal air leaks first before insulating. Caulk and weather-strip doors and windows, seal penetrations around plumbing or electrical penetrations, and add gaskets to electrical plates on exterior walls. These actions could save up to 10 percent on your annual heating and cooling bill.
- Add insulation to the attic first. According to the Department of Energy, approx. Twenty-eight percent of heat loss occurs through the roof. Since it is relatively easy to insulate an attic, this would be the best place to investigate first.
- Ventilate and insulate together. Not all areas of a house should be insulated; some portions should just be ventilated. It can be complicated to figure this out, so ask a general contractor, an architect or a local building official for advice.
- Use the proper insulation in the correct location: Spray foam is popular and fast, but not always appropriate. Blown cellulose has many redeeming qualities and may be the best option for an older home. Research insulation types and their properties in detail before you begin any work.
- Have an Energy Audit performed: If you don’t know where to begin, or want to know more about the specific needs for your home, contact an energy contractor who can perform an audit to pinpoint the exact energy needs that you might require. A listing of auditors can be found at www.michigan.gov/energyoffice.
Remember that older homes are just like people: They are all unique and have their own specific needs! Treat your older home with the specific care that it requires and you will do well to ensure its longevity and standing in the community.