Updated October 2026. Definitions and rating scales from the National Fenestration Rating Council (NFRC) and ENERGY STAR Version 7.0. How we research this Window salespeople tend to talk in labels like “Low-E,” “ENERGY STAR,” “argon-filled,” and “triple-pane.” None of these tells you how the specific window on your quote will perform. Two windows can both … Read more

Compare triple-pane vs double-pane using NFRC U-factor and SHGC. When the premium buys comfort and quiet — and when good Low-E double is enough.

Both are fiberglass and both claim to move with the glass. What actually separates them is how each warranty behaves: lifetime that changes on sale, or fixed terms that transfer.

Both put wood on the room side. One clads the exterior in vinyl, the other in fiberglass. Where that changes maintenance, finish coverage and the warranty you actually get.

Fog between the panes means the sealed glass unit has failed. Here is how to tell it apart from room-side condensation, what glass-only replacement restores, and what defogging does not.

Both are premium vinyl lines with foam-insulated or multi-chambered frames. The real difference is what each manufacturer publishes about its warranty, and how you buy them.

Two materials that compete for the same buyer, with opposite warranty philosophies: Andersen transfers its coverage, Marvin publishes component terms and no lifetime claim.

ProVia’s premium vinyl line, summarized from its own documentation: SunShield vinyl, foam-filled extrusions, and a lifetime warranty with two conditions most buyers never read.

Marvin’s all-fiberglass value line, summarized from its own documentation: what Ultrex is, what the Limited Warranty actually covers, and why it is not a lifetime warranty.

Andersen 100 Series (Fibrex composite) vs 400 Series (wood + Perma-Shield): what the two products actually differ on, and how to normalize an installed quote before treating either total as cheaper.