Special from CMHC
Make your home’s additions more energy-efficient
Common types of additions include older homes with large covered porches that have been closed in to create additional living space, upper floor dormers, simple one-room additions, garages or carports that have been converted to living space and sunrooms or solariums.
Additions can be heated by electric baseboards, a direct-vent gas-fired baseboard heater, a sealed or a direct-vent gas fireplace. The home’s furnace may be able to heat the addition but you’ll have to have a heating contractor check to see if it has enough spare heating capacity. Heating from the furnace will also require running ductwork to the addition. If you are installing ductwork, keep it within the heated space, or in a heated and well-insulated closed crawl space. If you have extended your forced-air heating to a closed-in porch or addition, make sure the supply and return air ducting is properly sized and installed.
You may be able to do some energy-efficient improvements yourself, depending on your comfort and knowledge level. For more complicated tasks, or those that deal with potentially hazardous materials, consult with a qualified contractor on how to get the work done safely and correctly.
Air sealing and insulating roofs, walls and foundations will reduce heat loss and improve comfort levels. Pay special attention to the air barrier and insulation in the areas where new construction joins the original house as there could be gaps that need to be filled and sealed. Other areas that often require insulation and air sealing include the top of foundation walls, around windows, ceiling penetrations, attic hatches, around light fixtures and wiring and service penetrations through exterior walls.
Dormers are especially prone to high rates of heat loss, as they are typically in the upper level of the house where the heat gathers. A well-sealed layer of rigid board insulation added to the interior of a dormer can reduce air leakage and heat loss significantly. It’s important to cover most types of rigid board insulation with drywall to prevent it from catching fire. Another important area to check is the connection between a crawl space under an addition and the adjoining basement, especially when the crawl space is heated.
Upgrading to energy-efficient windows can greatly improve comfort levels in all areas of your home, but especially in older enclosed porches and sunrooms or solariums that are used year round. North-facing glazing in sunrooms and enclosed porches can be replaced with double- or triple-glazed low-emissivity argon-filled windows to reduce heat loss and improve comfort.
Be aware that renovations can have risks. For instance, some types of insulation that you might find in the attics, or walls, of older homes may pose a health risk if disturbed. Electrical and plumbing work should always be done by a qualified contractor to protect your family and your house. 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.caor 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 .