
F-Series · Fiberglass
GR85 Casement Window
The 85 mm casement, detailed with an integrated pleated insect screen — Passive House-grade thermal depth in an outward-opening window that keeps insects out without a separate storm frame.
The same deep 85 mm fiberglass frame as the dual-action window, in an outward casement with a factory-integrated pleated screen. It suits Passive House elevations where operable ventilation and insect protection both matter.
Technical specifications
| Frame depth | 85 mm |
| Frame material | Pultruded fiberglass, powder-coated |
| Glazing pocket | Up to 42 mm |
| Opening | Casement, outward |
| Whole-window U-value, ZERO 04 | 0.127 Btu/h·ft²·°F (0.72 W/m²K), R-7.9, at NFRC size 600 × 1500 mm Calculated |
| Whole-window U-value, ZERO 05 | 0.130 Btu/h·ft²·°F (0.74 W/m²K), R-7.7 Calculated |
| Center-of-glass U-value | ZERO 04: 0.044 to 0.047 Btu/h·ft²·°F (R-21 to R-23) · ZERO 05: 0.054 (R-18.5) Calculated |
| Screen | Integrated pleated, retractable |
| SHGC, center of glass | KØLD 0.49 / 0.35 · MILD 0.35 / 0.27 · HEIT 0.26 / 0.20 (ZERO 05 / ZERO 04) Calculated |
| Visible light, center of glass | KØLD 76% / 64% · MILD 67% / 53% · HEIT 61% / 45% (ZERO 05 / ZERO 04) Calculated |
Certified values are published as NFRC and CSA testing completes. Calculated values come from LBNL THERM and WINDOW models of the specific assembly. Project-specific values depend on size and glass package.
What is a casement window?
A casement window is hinged on one side and swings open like a door, usually outward. Because the entire sash opens, it ventilates fully and catches side breezes, and the harder the wind pushes on it, the tighter it seals against the frame. Casements give an uninterrupted view and a slim sightline.
Thermal section (THERM heat map)

GR85 Casement Window · Sill, with insect screen. Whole window 0.127 Btu/h·ft²·°F (R-7.9) with ZERO 04, 0.130 (R-7.7) with ZERO 05, at 600 × 1500 mm. Calculated
Modeled in LBNL THERM 8.1 at NFRC winter conditions, 0°F outside and 70°F inside. The red band on the room side shows the frame and glass staying close to room temperature; the lines are isotherms every 3°C (5.4°F). On the GR85 the head and jambs use the same frame section as the sill.
Full engineering image ›All sections, ZERO 04 (PDF, 5.9 MB) ›ZERO 05 (PDF, 5.9 MB) ›Every section we model ›
Glass & glazing options
Standard glazing is the hybrid vacuum unit in one of six ZERO packages: three climates, each at two levels. ZERO 05 Daylight admits the most light and solar heat; ZERO 04 Ultimate has the lowest U-factor.
| Package | Center-of-glass U / R · SHGC · visible light |
| KØLD 05 · cold | 0.054 / R-18.5 · 0.49 · 76% |
| KØLD 04 · cold | 0.047 / R-21.1 · 0.35 · 64% |
| MILD 05 · mixed | 0.054 / R-18.6 · 0.35 · 67% |
| MILD 04 · mixed | 0.044 / R-22.6 · 0.27 · 53% |
| HEIT 05 · hot | 0.054 / R-18.6 · 0.26 · 61% |
| HEIT 04 · hot | 0.044 / R-23.0 · 0.20 · 45% |
Quanex Super Spacer® Premium silicone-foam warm-edge spacer, argon-filled outer cavity.
Triple glazing, laminated and acoustic build-ups are also available to suit the project. Compare the ZERO packages ›




