Top-Rated Window Replacement Companies in West Islip, NY
West Islip's 7 listings below come from Google Maps rather than a state license file. IECC climate zone 4A sets the energy bar for a West Islip window job no matter which kind of list a contractor's name comes from. Checked September 2026.
Google Maps ratings checked · How we rank
4AIECC climate zone · ENERGY STAR North-Central zone
Climate and energy performance in West Islip
Weather at that level is one more reason the flashing and sill pan under a West Islip window matter as much as the glass sitting in it.
So ask any West Islip contractor how they handle both, not just which brand they carry.
Data: U.S. EPA / DOE, ENERGY STAR, ENERGY STAR Version 7.0 Climate Zones by County/ZIP (Windows, Doors, and Skylights) (V7.0); Pacific Northwest National Laboratory (DOE Building America), Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates (PNNL-33270) (2021 IECC), from the nearest NOAA station 6.7 mi away.
Google's top window installers serving West Islip, NY
Ranked by Google rating weighted against how many people left one, so a perfect score from a handful of reviewers never outranks a strong average built on hundreds. That ranking is not a license check; call the state directly and ask for the contractor's license or registration number.
| Rank | Business | Google rating | Reviews | Category | Area | Google Maps listing |
|---|---|---|---|---|---|---|
| 1 | Mikita Door & Window of North Babylon | 90 | Window installation service | Not listed | Google reviews | |
| 2 | Window Nation | 114 | Window installation service | Deer Park 11729 | Google reviews | |
| 3 | V&P Siding & Window Corp | 42 | Window installation service | West Islip 11795 | Google reviews | |
| 4 | Royal Windows and Doors | 62 | Window installation service | Bay Shore 11706 | Google reviews | |
| 5 | F G GLASS SERVICES | 102 | Window installation service | Not listed | Google reviews | |
| 6 | Tri State Window Factory | 167 | Window installation service | Deer Park 11729 | Google reviews | |
| 7 | Baradzi Glass Inc | 20 | Window installation service | Bay Shore 11706 | Google reviews |
Questions to ask before you sign
- How long have you held your state license, and can I see the number?
- Is this a full-frame replacement or an insert into my existing frame, and why that one?
- Who pulls the permit, and does this change trigger an egress check on a bedroom window?
- What flashing and sill pan will you use, and in what order do you install them?
- If my home was built before 1978, is your crew lead-safe certified for this job?
- What's the completion date in writing, and what happens if the schedule slips?