Verified from the manufacturer’s own documentation · last checked September 19, 2026
| Manufacturer | Milgard |
|---|---|
| Series | Ultra Series C650 |
| Frame material | Fiberglass, produced by pultrusion. Milgard states the material resists swelling, rotting and warping and expands and contracts at approximately the same rate as the insulated glass, putting less stress on the seals. Four exterior frame colors in Milgard's C650 brochure (Frost, Harmony, Bark, Black Bean) with matching interior/exterior options for the popular dark-frame look |
| Styles / configurations | Milgard's operating styles in fiberglass — single-hung, horizontal slider, casement, awning, picture and specialty shapes; bay and bow; French swing and sliding French patio doors. Confirm the current C650 style range on Milgard's page |
| Glass options | Milgard SunCoat Low-E2 glass standard on dual-pane windows and patio doors; optional tinted, obscure and impact-resistant glass. Modern glass pane spacer technology available |
| U-factor | Not published as a single line-wide range; NFRC-certified performance follows the configuration. Check the NFRC label on the exact unit quoted |
| SHGC | Not published as a single line-wide range; follows the configuration. Check the NFRC label on the unit quoted |
| VT | Not publicly specified |
| ENERGY STAR | Milgard supplies ENERGY STAR options; certification follows the glass package and region |
| NFRC certification | NFRC-certified performance follows the configuration; per-series STC ratings and 3-part specifications are published in Milgard's technical resources for C650 |
| Warranty | For windows manufactured after January 1, 2026 and installed into an existing home (replacement), Milgard's Replacement Product Lifetime Limited Warranty applies: frame material covered for as long as the original owner owns and occupies the home (10 years for all other owners, including later buyers, rentals and commercial use). Insulated glass seal: 20 years; laminated/impact delamination: 10 years; stress cracks: 1 year. Painted or powdercoat finishes: 10 years. Hardware: 10 years; weatherstripping and screens: 1 year each. Skilled labor and shipping are provided for claims within 10 years of manufacture only if the home is inside Milgard's service territory. Claims within 30 days of discovery. The paid Full Lifetime upgrade is not offered on C650. New-construction installs use a separate Milgard warranty |
| Positioning | Milgard's premium contemporary fiberglass window and patio door line (a MITER Brands product). Positioned as the upscale, modern fiberglass alternative to the V300 Trinsic vinyl line. Awarded Most Used fiberglass window brand in the Western US in the 2020 Builder Magazine Brand Use Study |
| Price position | Premium fiberglass (contemporary) |
| Installation | New construction, replacement and remodeling; sold within Milgard's (Western-US) service territory through Milgard dealers |
Notes
Re-verified September 19, 2026. Corrections: previous summary said IGU 'and components' were 20 years — the 2026 document gives 20 years to the glass seal but only 10 years to hardware and 1 year to weatherstripping, screens and stress cracks; clarified that the warranty document itself transfers but frame coverage for later owners drops to 10 years; added that labor depends on Milgard's service territory and that new-construction installs have a separate warranty. Milgard sells mainly in western US states. Performance data is style- and glazing-specific — check the NFRC label
Sources
Milgard Replacement Product Lifetime Limited / 10-Year Limited Warranty PDF effective January 1, 2026 (milgard.com) for every warranty term, labor and territory condition; Milgard New Construction Warranty PDF effective January 1, 2026 to confirm a separate new-construction warranty exists; Milgard C650 product page and brochure for construction and colors