Just about any house can benefit from energy-efficient renovations such as increasing insulation levels and air sealing. In particular, post-1960s two-storey homes offer distinct opportunities to improve efficiency and lower energy costs. Some have an attached garage and maybe a room over the garage, along with a full unfinished or finished basements where energy saving retrofits might be possible.
Depending on your comfort and knowledge level, you may be able to do some of this work yourself. However for more complicated tasks, or those that deal with potentially hazardous materials, consult with a qualified contractor on how to best get the work safely done.
If you have an attached garage pay special attention to weather-stripping doors and sealing any crack and joints in walls and ceilings shared with the garage to stop exhaust fumes from entering the house. It’s also a good idea to insulate the common wall between the house and the garage to the same level as the rest of the exterior walls.
If there is a room above the garage, insulating the garage ceiling to an ‘effective’ insulation value of at least R-31can help save energy and make the floor of the room more comfortable. Because an effective insulation value takes account of heat loss through the wood framing as well as through the insulation, if possible consider installing insulation with an R-value slightly higher than 31 to compensate for the framing. Spray foam insulation can be a good option in this location as it insulates and air seals at the same time but it should be installed by a qualified contractor.
For a finished garage, loose-fill insulation could be blown-in through the joist cavities without too much damage to the finish but this should be done by a trained contractor to ensure the insulation is installed correctly and fills all the voids, especially the area where the floor joists meet the exterior walls. Sometimes, air sealing and insulating might best be accomplished by removing the garage ceiling to do the work.
Rooms above garages are usually not very airtight and may require a fair amount of work at the perimeter edges and penetrations. Check the floor-wall intersection for tell-tale signs of black carpet staining that can indicate air leakage. If a gap exists in this location, the baseboard may have to be removed, the carpet pealed back and caulking applied to the joint. Weatherproofing gaskets can also be installed behind the plates of electricity outlets and switches to reduce air leakage.
Windows are another common area for air leakage and moisture problems in older two-storey homes. Houses built in the 1970s may have aluminum frame “sashless sliders,” (where the glazing sits directly in tracks in the frame). You can reduce condensation problems by installing new sliders set in sashes or preferably replacing the complete window unit. New windows have much better energy performance than old ones and can reduce heat losses and drafts. Be sure to fill the gap between the window frame and wall with spray polyurethane foam to insulate and air seal the space. Existing wood-frame windows can be retrofitted using custom, double-glazed units in the original sash, but replacing the complete window can lead to better energy performance. When choosing new energy-efficient windows, look for a high-performance unit with selective glazing such as double- or triple-glazed units with a Low-e coating, argon-gas fill and insulating spacers.
Making energy-efficient improvements throughout your home will reduce energy use, drafts, moisture and condensation problems and help to improve your indoor air quality and overall comfort. The best time to carry out energy-saving improvements is when you are planning other renovations.
However, be aware that renovations can have risks. Some types of insulation that you might find in the attics, or walls, of older homes may pose a health risk if disturbed. Additionally, unless certain precautions are taken, air sealing can restrict indoor-outdoor air exchange to the point where humidity becomes a problem or combustion appliances may have trouble venting properly. Consulting qualified contractors can help inform you of safe approaches to your energy-efficient renovation.
To help you learn more about renovating for energy efficiency, Canada Mortgage and Housing Corporation (CMHC) offers a series of free Renovating for Energy Savings fact sheets that describe ways of saving energy in houses of all types and ages. Download the fact sheet that most resembles your home at www.cmhc.ca or call 1-800-668-2642.
Mark Salerno is the Corporate Representative for the Greater Toronto Area at Canada Mortgage and Housing Corporation. You can reach him at 416-218-3479 or e-mail him at firstname.lastname@example.org.
By Mark Salerno, special from CMHC