Choosing insulation for your home
Home insulation slows the flow of heat out of the house in winter and into it in summer. The main choices are batts, loose-fill, rigid board, mineral wool and spray foam, and the best one depends on where it goes, how much space there is and how well the area is air sealed.
What does insulation actually do?
Insulation is any material that resists heat flow, usually by trapping still air in small pockets. Its strength is measured by R-value, or RSI in metric. The higher the number, the slower the heat escapes through that layer. Insulation works together with an air barrier, because moving air carries heat past even a thick layer. The reasons are covered in more detail in air sealing a house, and the numbers behind recommended levels are in R-values by region.
What are the main types of insulation?
- Batts and rolls. Fibreglass or mineral wool cut to fit between studs and joists. Cheap, but gaps and compression cut performance.
- Loose-fill. Cellulose or fibreglass blown into attics and some wall cavities. It fills irregular spaces, see cellulose versus fibreglass.
- Rigid board. Foam or mineral boards for basements, exterior walls and roofs. They resist moisture and add continuous coverage.
- Spray foam. Seals and insulates at once, at a higher price, explained in spray foam insulation.
Each has its own safety and handling points, and installers should be able to name the product and show its technical sheet.
Where should a house be insulated?
Heat leaves through every part of the envelope, but the share differs by house. The attic and roof usually matter most, with the walls, foundation and floors over cold spaces after that. In an older house, leaks around the attic floor and rim joist often matter as much as the insulation itself. Start with the attic, then look at the basement, and consider walls last because they are the hardest and costliest to change. The order is set out in the upgrade priorities guide.
How do you choose the right insulation?
Ask four questions. Is there enough space to reach the target R-value with a cheaper material? Is moisture a risk in this location? Can the installer seal air leaks as part of the job? Does local code require a particular vapour or fire treatment? A material that is perfect in a dry attic may be a poor choice against damp concrete. Mixed approaches are normal: for example, foam at the rim joist and blown fibre in the attic.
Do not forget ventilation. As houses get tighter, they need controlled air change, which a heat recovery ventilator provides. Efficient new houses are designed around this, as in the R-2000 standard.
How does insulation connect to heating and Drake Landing?
Less heat loss means a smaller heating load, which makes any system cheaper to run and easier to size. The 52 homes at Drake Landing were built to R-2000 so that a modest solar and storage system could carry most of their space heating, as the how it works page explains. The same logic helps a retrofit: reduce the load first, then choose the heating. A home energy audit measures where you stand. Incentive programs for insulation come and go, so check the Government of Canada energy-efficiency pages, your province and your utility for the current terms before booking work.
Quick answers
Which insulation has the highest R-value per inch?
Foam products generally have more R-value per inch than fibreglass or cellulose. Higher R per inch matters most where space is limited.
Can I insulate my house myself?
Dry, accessible spaces such as an open attic are manageable for a careful owner. Wet areas, foam and anything near wiring, flues or asbestos need trained trades.
Does insulation need a vapour barrier?
Many assemblies need some form of vapour control, but the right layer depends on climate, materials and code. Ask your building department or contractor.