Upgrade existing windows
Both sash replacement and whole-unit replacement significantly improve the performance of windows.
The space between the rough opening and the window unit, however, must be insulated and air sealed as part of the upgrade to see real benefits. In most cases, this can be done simply by removing the existing interior trim, sealing, then replacing the trim. The best seal is a continuous bead of minimally expanding foam.
Learn more in the Green Building Encyclopedia
Profiled in our Product Guide
