What does a window warranty actually cover and what's usually excluded?

Window warranties can be confusing because manufacturers often make them sound comprehensive when they actually have significant limitations. Understanding what's covered before you buy can save you a lot of frustration down the road.

What's Typically Covered

Most quality window warranties include two separate components: a glass unit warranty and a frame/hardware warranty. The glass unit warranty (usually 10-20 years, sometimes "lifetime") covers seal failure — when the inert gas (argon or krypton) escapes and you see fogging or condensation between the panes. The frame warranty covers defects in materials and workmanship, meaning warping, cracking, or delamination that isn't caused by external damage or misuse.

Hardware coverage (locks, handles, hinges, operators) is typically covered for a shorter period — often 1-5 years — since these are mechanical parts that wear with use. Some premium manufacturers like Andersen or Pella offer more robust hardware coverage, so it's worth comparing.

What's Almost Always Excluded

This is where homeowners get surprised. Most warranties exclude labour costs for replacement, meaning even if the glass unit is covered, you may pay $150-$300+ per window just to have it swapped out. Other common exclusions include damage from improper installation, condensation on the exterior or interior surface (which is a humidity issue, not a defect), acts of nature, paint or finish damage from cleaning products, and normal wear.

Transferability is another important factor. Some warranties are non-transferable, which affects your home's resale value. If you're selling your Ottawa home, a transferable lifetime warranty is a meaningful selling point.

The Installation Warranty Matters Just as Much

A window is only as good as its installation. Even a perfect product will fail prematurely if it's improperly flashed, shimmed, or air-sealed. Always ask your installer for a separate installation warranty — reputable Ottawa installers typically offer 1-5 years on their workmanship. Ottawa's freeze-thaw cycles are particularly hard on poorly installed windows, so this coverage matters more here than in milder climates.

When comparing quotes, ask each supplier to hand you the actual warranty document — not just a summary card. Look specifically for the labour reimbursement clause, the transferability terms, and the list of exclusions. If you'd like help evaluating warranty options for your specific project, Ottawa Window Pros offers free consultations and works with manufacturers whose warranties hold up in the real world.