Verified from the manufacturer’s own documentation · last checked September 19, 2026
| Manufacturer | OKNA |
|---|---|
| Series | Insul-Tec / 500 Series |
| Frame material | Vinyl. Maintenance-free rigid multichamber vinyl profile. Full 3-1/4" depth welded mainframe with beveled colonial exterior. Full integral interlock with double weather-stripping. Standard Euro-White or optional Almond vinyl; seven exterior stock color selections plus virtually unlimited custom paint colors. Balance covers standard |
| Styles / configurations | Double-hung (DH500 flagship), single-hung, picture / fixed, horizontal slider, hopper. Available as replacement or new construction (nailing fin or flange with J-channel). Confirm the current Insul-Tec style range on OKNA's page |
| Glass options | Heatseal warm-edge spacer system standard; Duralite spacer on the 500 series (earlier generations used aluminum box-channel spacer). Low-E insulating glass with argon options. Fusion-welded sloped sill (no weep holes — Insul-Tec uses a design that drains water at the sill to the outside) |
| U-factor | Third-party industry references quote a typical DH500 Insul-Tec configuration at U-factor 0.25, SHGC 0.28, DP50, AI 0.02 (Low-E and argon). Configuration-dependent — check the NFRC label on the exact unit quoted |
| SHGC | Third-party references quote SHGC 0.28 for a typical DH500 configuration; follows the glazing package. Check the NFRC label on the unit quoted |
| VT | Not publicly specified |
| ENERGY STAR | OKNA Insul-Tec is ENERGY STAR-qualifying in most climate zones with the appropriate glass package |
| NFRC certification | NFRC-certified performance follows the configuration; check the NFRC label on the exact unit quoted |
| Warranty | OKNA Windows Lifetime Limited Warranty. uPVC frame and sash: lifetime against blistering, peeling, flaking, corroding and fading while you own the home. Insulated glass (including internal grids): lifetime against seal failure; stress cracks 1 year; units with internal mini-blinds 10 years; gas-fill levels not warranted. Hardware: lifetime operating condition; specified metal hardware for coastal applications 10 years; patio door screen hardware 10 years. Factory exterior paint: 10 years. Transferable one time to the next homeowner. Commercial, rental or multi-family use: 10 years, not transferable. OKNA supplies parts or product to the certified dealer; labor, shipping and reinstallation are NOT covered. The owner must notify the dealer within 30 days of the defect first appearing. OKNA's separate Lifetime Limited Glass Breakage Warranty is for the original homeowner only and not transferable. Contains a class-action, arbitration and jury-trial waiver (Pennsylvania law, Bucks County) |
| Positioning | OKNA's mid-tier flagship vinyl replacement window — the entry point of OKNA's premium range (500 Insul-Tec / 600 Eco Pro / 700 Casements / 800 Enviro-Star / 900 Starmark). Positioned as a best long-term-value vinyl replacement by independent industry reviewers. OKNA is a New Jersey-based manufacturer with a mostly-northeast dealer distribution — not sold through home centers |
| Price position | Mid-range vinyl (regional premium) |
| Installation | Replacement (primary) and new construction; sold through OKNA's authorised dealer network in a mostly-Midwest and Northeast US regional footprint |
Notes
Vinyl. Re-verified September 19, 2026 against OKNA's own warranty document and restored to the public catalog. Correction: the record said the insulated glass drops to 10 years in East Coast salt-air markets — OKNA's warranty gives the glass seal lifetime coverage; the 10-year coastal limit applies to specified metal hardware. Added the one-time transfer, 30-day notice rule, labor exclusion and commercial terms. OKNA's current literature lists the line as the '500 Series'; 'Insul-Tec' could not be confirmed on a current OKNA page, and the product link has not been re-confirmed — open items. Regional manufacturer (Bristol, PA). Performance data is style- and glazing-specific — check the NFRC label
Sources
OKNA Windows Lifetime Limited Warranty PDF and OKNA Lifetime Limited Glass Breakage Warranty PDF, both hosted on OKNA's document store (media.cmsmax.com/d3xadgynuglafnjbqq2la, which also hosts OKNA's 2023 Bay & Bow brochure listing the 500 Series); a dealer-hosted copy of the same warranty dated November 2023 matches the text