Exterior Insulation
Rigid insulation under siding is increasingly popular—and often recommended or required in some parts of Canada—due to our cold climate and focus on energy efficiency. It plays a key role in improving your home's thermal performance, air sealing, and moisture resistance, especially when updating or building exterior walls. Exterior insulation acts to reduce thermal bridging in the stud area of the wall —a major source of heat loss through wall studs.
Exterior insulation under siding makes the most sense when siding is already being replaced or during a major renovation where the siding is already removed. This allows for a cost-effective way to improve the building's insulation and air sealing without incurring the expense of removing existing, functional siding. It's also beneficial in colder climates where extra insulation can significantly reduce heat loss and improve energy efficiency.
Why it's a good idea:
Improved Energy Efficiency:
Exterior insulation creates a continuous thermal barrier, reducing heat transfer and lowering energy consumption for heating and cooling.
Comfort and Noise Reduction:
By minimizing drafts and stabilizing indoor temperatures, exterior insulation enhances comfort and reduces noise infiltration.
Air Sealing: Insulation can be installed in a way that improves air sealing, reducing air leaks and drafts.
Cost-Effective (When Siding is Replaced):
The cost of adding insulation during a re-siding project is minimal compared to the cost of removing siding solely for insulation purposes.