Side by side
| Vinyl | Fiberglass | |
|---|---|---|
| Average installed cost (This Old House, 2026) | $472 | $564 |
| Typical lifespan | 20-40 years | 40+ years |
| Strength | Good; wider frames | Very strong; slimmer frames, more glass |
| Expansion in heat | More | Very little (similar to glass) |
| Paintable | Not easily | Yes |
| Maintenance | Very low | Very low |
Choose vinyl if
You want the best value, live in a moderate climate and are happy with white, tan or a limited color range.
Choose fiberglass if
You plan to stay in your home for a long time, live with extreme heat or cold, want dark colors or slimmer frames, or might repaint.
See prices: vinyl windows · fiberglass windows.
Looks and colors
Vinyl frames are usually wider and come in a limited set of colors, though many makers now offer dark exterior laminates. Fiberglass can be painted and its slimmer frames let in more light: closer to the look of wood.
Climate considerations
In places with big temperature swings or intense sun, vinyl expands and contracts more than fiberglass, which can stress seals over time. Fiberglass expands at a rate close to glass, so seals stay tighter. In mild climates, good vinyl performs well for decades.
Cost over time
Fiberglass costs about 20% more upfront on average ($564 vs $472). If it lasts significantly longer and you stay in the home, the yearly cost of ownership can be similar or lower. If you’re likely to sell within a few years, vinyl usually makes more financial sense.
Other options
Composite frames (like Andersen’s Fibrex) sit between the two on price, and wood remains the choice for historic homes. See all window costs by material.
