Natural Resources Canada's Office of Energy Efficiency offers this guide to educate on basic principles of building science and to provide guidance in home retrofit projects such as insulation and air sealing improvements.
Learn How to Conserve Heat in Your Home
Remodeling, renovating or upgrading your home? The following information is designed to guide you in upgrading the energy performance of your home. Whether you do the work yourself or hire an expert professional contractor, you will have a good understanding of how to do the job or ensure that it is done properly.
Understanding how your house works before starting a retrofit will help ensure that the job meets your expectations and that you will not be causing new issues while resolving old ones. This section explains how building science principles can help you control the flow of heat, air and moisture / humidity, and why you must consider these factors together. From your bedroom to your basement, the heating and cooling system plays an important part of improving the comfort of your home, reducing your energy bills and helping reduce harmful greenhouse gases (GHGs).
Whether for your attic or your basement, choosing the right materials and installing them properly ensures the finished job lives up to your expectations. This section describes the types of insulations, house wrap materials (air barriers and vapour barriers) as well as details about weatherstripping windows and doors.
Air leakage control is the single most important retrofit activity, and it should be considered first in any upgrade strategy for your house. Air leakage control is essential, so every time you insulate, install or upgrade the air barrier system, ensure that moisture does not enter the insulation or building envelope. Comprehensive air leakage control is the systematic identification and sealing of as many air leakage paths as possible with weatherstripping and caulking and by applying gaskets and tapes. Did you know that your windows, doors, cracks in the walls, interior trim and even light fixtures in the ceiling are potential leakages areas?
Relatively easy access has made the attic a favourite starting point to insulate for many homeowners, despite the fact that most other areas, such as basements and uninsulated walls, lose more heat than the typical attic. Even if an attic is already insulated, there may still be an opportunity to improve the energy efficiency and soundness of the house through air sealing and ventilation. Air leaks via the chimneys, vents, plumbing pipes and electrical boxes in the attic can account for substantial heat loss and can lead to a variety of moisture-related problems. The importance of air sealing cannot be overstated. If you are upgrading your attic, read this entire section for helpful tips and other relevant information.
Basements can account for about 20 percent of a home’s total heat loss. This is due to the large, uninsulated surface area both above and below grade level. Contrary to popular opinion, earth is a poor insulator. There is also a lot of air leakage through basement windows and penetrations (including cracks in these areas) and at the top of the foundation wall (sill area). Many basements have little or no insulation, so this means there is much potential for improvement. Insulating can often be tied in with other repairs or renovation work such as waterproofing, radon remediation or finishing the basement.
Walls can account for about 20 percent of heat loss in houses. In addition to heat loss through the walls, there are many cracks and penetrations that allow uncontrolled air leakage into and out of the house. If you are planning to renovate the inside or the outside of your home, this section will provide information about the types of walls within a home as well as how to get the most out of your home improvements.
Windows and doors can account for up to 25 percent of total house heat loss. Windows and doors can be repaired, however at times it is best to replace them with more energy-efficient models. Proper installation and maintenance also play a key role in saving energy and improving comfort. Learn about upgrading or replacing windows and doors.
Like any system, your house will run only as efficiently as you operate and maintain it. Operating it efficiently will maximize your retrofit gains and can actually improve your home's heating, cooling and ventilation performance and overall durability. Even more important, you will create a healthier, more comfortable living environment. As part of your house as a system, a well-tuned and efficiently operating heating, ventilating and air-conditioning (HVAC) system can significantly reduce your annual energy bill.