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