Direct Answer
The best window replacement contractors in Denver are verified through Colorado DORA Electrical/Plumbing Board (dora.colorado.gov). Look for companies with 4.5+ Google stars, 50+ reviews, active CO license, and at least 5 years serving the Denver area.
Full Explanation
Verify any Denver contractor at Colorado DORA Electrical/Plumbing Board (dora.colorado.gov). Request proof of general liability insurance and workers' compensation. Ask for references from recent Denver projects — local experience matters for understanding permit requirements and area-specific challenges.
Local Factors in Denver
📍Verify license: Colorado DORA Electrical/Plumbing Board (dora.colorado.gov)
📍Denver city permit office issues local permits
📍Check BBB Greater Denver chapter
📍Require CO state license + local city license if applicable