Top-Rated Window Replacement Companies in South Portland, ME
South Portland's 10 listings below come from Google Maps rather than a state license file. IECC climate zone 6A sets the energy bar for a South Portland window job no matter which kind of list a contractor's name comes from. Checked October 2026.
Google Maps ratings checked · How we rank
6AIECC climate zone · ENERGY STAR Northern zone
Climate and energy performance in South Portland
IECC rates South Portland's climate zone as 6A, the starting point for any code-minimum window performance here.
ENERGY STAR places Cumberland County in its Northern zone for window certification.
Normal temperatures run 24°F in January and 70°F in July, so the glass package worth paying for in South Portland isn't the same one that pencils out two zones over.
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 1.5 mi away.
Google's top window installers serving South Portland, ME
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 | Pella Windows and Doors Showroom of Scarborough, ME | 177 | Window installation service | Scarborough 04074 | Google reviews | |
| 2 | Regal Replacement Windows | 43 | Window installation service | Portland 04103 | Google reviews | |
| 3 | M & Son Construction | 75 | Window installation service | Portland 04103 | Google reviews | |
| 4 | A-BEST Window | 112 | Window installation service | South Portland 04106 | Google reviews | |
| 5 | The Maine Window Company | 25 | Window installation service | Not listed | Google reviews | |
| 6 | Portland Glass of Portland | 367 | Window installation service | Portland 04102 | Google reviews | |
| 7 | Window World of Southern Maine | 153 | Window installation service | Westbrook 04092 | Google reviews | |
| 8 | Maine Windows and Doors | 25 | Window installation service | Portland 04103 | Google reviews | |
| 9 | Marvin Design Gallery by Eldredge | 8 | Window supplier | Portland 04101 | Google reviews | |
| 10 | Paradigm Windows | 69 | Window supplier | Portland 04103 | 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?