Guide
Aluminum vs vinyl vs fiberglass
Frame material is the first real decision in a residential replacement, and the honest answer is that all three are legitimate for different priorities.
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Aluminum gives the narrowest frames and the most glass, and needs a thermal break to perform. Vinyl is the cheapest and the widest. Fiberglass sits between them on both counts.
Aluminum
Aluminum is stiff, so the frame can be narrow and still carry a large piece of insulated glass. In a replacement, that usually means recovering glass area rather than losing it, and it is the reason aluminum dominates commercial work.
The trade-off is that bare metal conducts heat. A modern residential aluminum window solves this with a polyamide thermal break separating the interior and exterior extrusions, which is what makes the assembly energy-code compliant. Finishes are factory-applied and never need painting, and coastal-grade finishes are available where salt exposure matters.
Vinyl
Vinyl is the least expensive option and insulates well as a material. Because it is not stiff, the frame and sash have to be substantially wider to carry the same glass, so a vinyl replacement in an existing opening visibly reduces the glass area.
It also moves with temperature more than the alternatives, and the color is what it is — dark colors in full sun are a known weak point.
Fiberglass
Fiberglass is dimensionally stable and expands at nearly the same rate as the glass it holds, which is good for long-term seal life. Frames are narrower than vinyl but wider than aluminum, and the price sits between the two.
- Most glass area
- Aluminum, by a clear margin at the same rough opening.
- Lowest cost
- Vinyl, with the widest frames as the trade.
- Middle ground
- Fiberglass, stable and paintable, priced between.
What this site quotes
We quote aluminum-framed units specifically, commercial and residential. If vinyl is the right answer for your budget and priorities, that is a legitimate choice — it is simply not what this product line is.
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The quote form branches by buyer type, so you only answer the questions that apply to your project.