10 Questions to Ask a Door Replacement Contractor
The 10 Questions — and Why Each One Matters
A contractor who answers these confidently, with specifics, is demonstrating the transparency and competence that separates good work from mediocre work.
“Are you licensed in my state, and can I see your current liability insurance?”
Why this matters: Licensing requirements vary by state. Liability insurance protects your home if something goes wrong during installation; verify the policy is current, not expired.
“What is the door material, and what's the specific brand and product line?”
Why this matters: Steel, fiberglass, and wood perform very differently. Ask for the specific brand and series — not just "fiberglass door" — so you can research the warranty and independent reviews yourself.
“Is this door ENERGY STAR certified, and what's the glass package?”
Why this matters: For doors with glass — sidelights, transoms, or full-glass patio doors — the glass package (low-E coating, gas fill, number of panes) drives both energy performance and cost. Ask for the specific U-factor.
“How do you handle discovery of rotted framing at the rough opening?”
Why this matters: Rot in the door frame is common, especially on older homes. Ask what happens when they find it: a fixed price per linear foot of framing replacement, or hourly? Get this in writing before demo begins.
“What does your installation warranty cover, separate from the manufacturer's product warranty?”
Why this matters: Product warranties cover the door and glass; installation warranties cover the contractor's workmanship — flashing, sealing, and framing. Ask specifically what's covered if a draft or leak appears in year 2.
“Are you a certified installer for the door brand you're selling?”
Why this matters: Some manufacturers require certified installation for the warranty to remain valid. Ask to see the certification for the specific brand and confirm your installation won't void it.
“Will you replace the threshold and weatherstripping as part of this job?”
Why this matters: A full door replacement should include a new threshold and weatherstripping, not just the door slab and frame. Ask specifically what's included versus what's an upgrade.
“How long will the installation take, and is it a same-day job?”
Why this matters: A single door replacement typically takes 3–5 hours. Patio doors and custom sizes take longer. Ask what happens to your home's security if the job runs past a single day.
“Do you offer financing, and what are the terms including APR?”
Why this matters: Many door contractors offer 0% financing for a promotional period. After that period, rates often jump significantly. Know the full terms before using contractor financing.
“Can you provide references from door installations completed in the last 6 months?”
Why this matters: Recent references reveal current quality and communication. Ask references specifically whether the door seals well, whether the timeline held, and whether they'd hire this contractor again.
Red Flags to Watch For
Any of these during your contractor search should prompt closer scrutiny or disqualification:
- Same-day pricing pressure with a deadline
- Vague about the specific door brand and product line being installed
- Offers to skip permits on a structural opening change to "save you money"
- No written warranty terms — verbal guarantee only
- Significantly lower bid without explanation of what's different
- Can't provide proof of insurance within 24 hours