Choose windows for Canadian climate

U-factor, Energy Rating, air leakage and solar gain address different problems.

Prepared by RenoAtlas.ca · Last checked: 2026-08-01 · editorial method

Conceptual diagram — actual details depend on the home, product and local requirements.

What you will know after this guide

A lower U-factor generally indicates slower heat loss.

Energy Rating combines several effects and helps compare certified products overall.

A good window poorly connected to drainage and air barriers can remain uncomfortable and cause damage.