In recent years energy efficiency has prompted changes to the Ontario Building Code. These changes have created significant improvement in energy efficiency through advancements in the building and thermal envelopes of the home.
The building envelope is the outer layer of the building structure that physically separates the inside living space from the outdoor environment. An energy efficient building envelope limits air movement into and out of the house. The more continuous the thermal envelope is and the higher the insulation levels are, the more energy efficient the home is.
New homes are more efficient today than ever before. Advances in building science and improvements in technologies, techniques and building materials have lowered operating costs and increased comfort levels.
In 2012 an additional air barrier inspection by City building inspectors became mandatory. This inspection is meant to ensure that all penetrations through the building envelope are properly sealed thus preventing building envelope failures.
Because new homes are so tightly sealed it is necessary to install Heat Recovery Ventilators (HRV) to introduce fresh air and ensure the quality of indoor air in the home. In the winter, an HRV system exchanges stale air from inside the home with fresh outdoor air. To ensure absolute comfort and energy conservation the system captures heat from contaminated air before it is exhausted outdoors. The system works in reverse during the summer months capturing the cold from the indoor air before it is exhausted outside.
In an older home there are a number of improvements that can be made for greater energy efficiency, comfort and reduced operating costs. Draft proofing is first and foremost on the list of items that should be addressed. Air leakage can make a home uncomfortable and costly to operate. Often areas of air leakage can be addressed with simple caulking. Seal around windows, doors and any penetrations through the exterior walls of your home. Inside your home you can seal around window and door casings, baseboards, attic hatches, electrical boxes and anywhere else you notice a draft. Weather stripping around doors and windows should be kept in good condition. In an unfinished basement the area between the top of the foundation wall and wood framing is a likely source of draftiness. Ensure that this area is sealed and insulated.
Exterior doors and windows are a critical part of the building and thermal envelope of any home. Older windows and doors can be a major source of heat loss. Consider replacing your doors with new metal or fibreglass insulated units and replace drafty windows with new energy efficient windows. Not only will these improvements increase energy efficiency they will lessen outside noise and improve the look and resale value of your home.
Increased insulation levels in an older home can provide great improvement to the thermal envelop. Attic insulation is normally easily upgraded. An R value of 50 is optimum. Proper soffit and roof ventilation is also very important. Exterior wall insulation is more difficult to upgrade. If there is no existing wall insulation certain types of insulation can be blown into wall cavities through holes drilled from the exterior or interior. Basement foundation walls should also be insulated. Full height insulation with an R value of 12 to 20 is preferred.
Improvements made to the energy efficiency of an older home, may not be as glamorous or aesthetically appealing as a kitchen or bathroom renovation but it is the most practical place to start and will give the greatest payback by reducing your heating and cooling costs and making your home more comfortable to live in.