Verified from the manufacturer’s own documentation · last checked September 19, 2026
| Manufacturer | Kolbe |
|---|---|
| Series | Forgent Series |
| Frame material | Glastra: Kolbe's proprietary hybrid of fiberglass and UV-stable polymer, in multi-chambered 'ladder' extrusions with AccuForge welded sash and frame corners. Two configurations: All-Glastra (interior and exterior in Cloud, Sahara, Midnight or Bronze; Cloud and Sahara are integral colors) or Glastra exterior with a pine interior (Double Clear Coat, Latex Primer, Black Paint, White Paint or stains). Tungsten is an exterior-only finish on units with Cloud interiors; Midnight and Bronze acrylic films are available. Impact units meeting IPD4 are offered for hurricane-prone coastal areas |
| Styles / configurations | Casement, awning, double-hung, horizontal sliding, direct set / picture (new construction and replacement direct-set), plus specialty shapes. Also Forgent Series inswing and sliding patio doors. Confirm the current style range on Kolbe's Forgent pages. Casement units achieve impact certification in hurricane IPD4 without additional reinforcement |
| Glass options | Low-E insulating glass with a stainless-steel spacer bar (standard); performance divided lite (PDL) grille system; multiple grid patterns and widths. Not all glass options are available on every Forgent product |
| U-factor | Not published as a single line-wide range; NFRC-certified performance follows the style and glazing package. Check the NFRC label on the exact unit quoted |
| SHGC | Not published as a single line-wide range; follows the glazing package. Check the NFRC label on the unit quoted |
| VT | Not publicly specified |
| ENERGY STAR | Kolbe offers Forgent glass packages that meet ENERGY STAR guidelines across US climate zones; certification follows the selected package |
| NFRC certification | NFRC-certified performance follows the configuration. Impact certification available for hurricane IPD4 on casement units. Low-E insulating glass with stainless-steel spacer carries a 20-year warranty per Kolbe's product pages |
| Warranty | Kolbe Window and Door Express Limited Warranty (effective November 21, 2025), which now covers Forgent Series together with Heritage, Ultra and VistaLuxe WD LINE. Extends to all first end users and transfers to later owners for the remaining term. General product: 10 years. Insulated glass seal: 20 years up to 60 sq ft (replacement glass only), 10 years at 60 sq ft and larger; non-tempered stress cracks: 5 years. Optional acrylic film / base product color fade: 20 years (first 10 years full, then prorated). Within 5,000 ft of salt water, Forgent exteriors are covered 10 years against abnormal corrosion or loss of adhesion. Hardware: 10 years; interior factory finish: 5 years; weatherstripping, screens and motorized parts: 2 years. Environmental corrosion of Glastra surfaces and acrylic films is excluded. Labor and travel are NOT covered. Written claim within 30 days of discovery |
| Positioning | Kolbe's efficient, fast-lead-time composite line, distinct from the aluminum-clad wood Ultra Series, contemporary clad-wood VistaLuxe and all-wood Heritage Series. Positioned as a builder-friendly Glastra-based option with short lead times, three installation methods (integral nailing fin, installation clips, screw through frame) and both new construction and replacement configurations. Mid-tier in Kolbe's residential range |
| Price position | Mid-range (Kolbe's composite/fiberglass-hybrid tier) |
| Installation | New construction and replacement; sold through Kolbe's dealer network (not through home centers) |
Notes
Glastra (fiberglass/polymer hybrid). Re-verified September 19, 2026 against Kolbe's Forgent pages and the November 2025 Express Limited Warranty. Corrections: Tungsten is exterior-only (it was listed as an all-Glastra interior color); corner construction is Kolbe's AccuForge welding; warranty rebuilt from the current document (Forgent is no longer on a separate Forgent-only warranty; labor excluded; acrylic film fade coverage prorated after year 10). Performance data is style- and glazing-specific — check the NFRC label
Sources
Kolbe's own Forgent Series pages — kolbewindows.com/product-lines/forgent-series/ (Glastra material composition, dual interior options, exterior finishes, style range), kolbewindows.com/windows/forgent-casement/ (impact IPD4 certification, 20-year IGU stainless-steel spacer warranty), kolbewindows.com/windows/forgent-new-construction-direct-set/ and forgent-replacement-direct-set/ for the installation methods and warranty statement; Kolbe Forgent Series Express Limited Warranty PDF (s3.us-east-2.amazonaws.com/dyke-site-assets/resources/uploads/Morgan-Wightman/warranties/KOLBE ForgentSeries WARRANTY.pdf) — full transferability, 10-year non-glass, 20-year stainless-steel-spacer IGU coverage, environmental exclusions; Kolbe warranty index (kolbewindows.com/resources/warranties/) for the effective-date structure