Direct Answer
To hire a reliable commercial glass & curtain wall installation contractor in Denver: (1) Get 3 written quotes with line-item breakdowns, (2) Verify CO license at Colorado DORA Electrical/Plumbing Board (dora.colorado.gov), (3) Confirm active general liability and workers' comp insurance, (4) Check Google and BBB reviews specific to Denver projects, (5) Never pay more than 10-30% upfront — never pay in full before completion.
Full Explanation
Red flags specific to Denver contractors: no physical Denver-area address, pressure to start immediately, cash-only payment demands, and license numbers that don't verify at Colorado DORA Electrical/Plumbing Board (dora.colorado.gov). Seasonal demand during summer brings out less reputable contractors.
Local Factors in Denver
📍Verify license: Colorado DORA Electrical/Plumbing Board (dora.colorado.gov)
📍File complaints: Colorado DORA Electrical/Plumbing Board (dora.colorado.gov)
📍Homeowner protections under CO consumer protection law
📍BBB Greater Denver chapter for complaints history