Price difference
From one Long Island company’s published price list (checked November 2026):
| Door | Non-insulated | Insulated |
|---|---|---|
| Single-car steel (8x7 or 9x7) | $1,550 | $1,995 |
| Two-car steel (16x7) | $2,500 | $2,950 |
Across all our sources, single-car steel doors ran $1,550 – $1,995 installed. See the price survey.
Which Long Island garages benefit most
- Attached garages, which are most of the garages on postwar Long Island ranches and split-levels.
- Garages under bedrooms, common in split-levels across towns like Commack and Syosset.
- Garages used as a gym, workshop or laundry space.
- Doors facing the wind on open or waterfront lots.
Other reasons people choose insulated doors
- Quieter. Insulated sections dampen rattling.
- Stiffer. Less flexing and denting.
- Better-looking inside. Many have a finished steel back.
How to compare thermal performance
Core material and thickness matter (polyurethane generally insulates better than polystyrene at the same thickness), but so do the seals and section joints. DASMA publishes guidance on rating the thermal performance of whole garage doors. Ask the installer for the whole-door rating, and replace worn weather seals at the same time.
Need it done? Call for garage door replacement & installation on Long Island. Local guides: garage door repair in Dix Hills, garage door repair in Commack.
Frequently asked questions
How much more is an insulated garage door on Long Island?
On one published Long Island price list, insulated single-car steel doors started at $1,995 versus $1,550 non-insulated, and two-car doors at $2,950 versus $2,500.
What R-value should a garage door have?
Compare doors by the whole door's thermal performance where the maker publishes it, not only the core material's R-value. DASMA publishes guidance on rating garage door thermal performance.
Does an insulated garage door help in summer?
Yes. It slows heat gain in a sunny garage as well as heat loss in winter, which helps rooms above or next to the garage.