Here's an industry truth: most window problems homeowners live with — drafts, leaks, doors that drag, trim gaps — are installation problems, not product problems. Which means the most important decision in your project isn't the brand of window. It's who you let install it.
After years in Twin Cities homes, here's exactly what we'd check before hiring any window contractor — including us.
Verify the license — it takes two minutes
Minnesota requires residential building contractors to be licensed through the Department of Labor and Industry (DLI). Ask for the license number and verify it on the DLI website, where you can also see complaint and enforcement history. A license means the contractor carries required insurance, has passed examination requirements, and — critically — your project is backed by the state's Contractor Recovery Fund if things go badly. Unlicensed "handyman" window installs forfeit those protections.
Insurance and workers' comp protect you
Ask for certificates of general liability insurance and workers' compensation. If an uninsured worker is injured on your property, you can be exposed. Legitimate contractors provide certificates without hesitation — hesitation is your answer.
A quote you can actually compare
A meaningful written quote specifies:
- Window brand, series, material, and glass package (with U-factor) for every opening.
- Insert vs. full-frame scope, stated per window.
- Interior and exterior trim details, insulation and sealing method, and flashing approach.
- Rot repair pricing or a stated contingency rate.
- Haul-away, cleanup, project timeline, and payment schedule.
- Both the manufacturer's warranty and the contractor's own labor warranty, in writing.
Red flags that should end the conversation
The window industry has a high-pressure sales wing, and its tactics are recognizable: a "today-only" price that expires when the salesperson leaves your kitchen, an opening quote that magically drops 40% after a phone call to the manager, three-hour in-home presentations, and demands for large deposits before measurement. None of that is how quality contractors operate.
Also be wary of quotes dramatically below the pack — the money usually comes back out of installation labor, the part of the project you can't see.
Questions that reveal real installers
Ask: Who actually installs — your employees or subcontractors, and who supervises? How do you insulate and seal the frame gap? What do you do when you find rot? Can I see local references or recent projects? Confident, specific answers signal a company that installs for a living. JMB Builders welcomes every one of these questions — free in-home estimates across the Twin Cities metro at 763-204-2099.
