Current fiberglass cost benchmark
Modernize lists a 2026 installed fiberglass benchmark around $900–$1,400 per standard-size window. Its dedicated fiberglass guide also shows lower-to-mid four-figure ranges depending on product and installation.
- ✓Low maintenance
- ✓Strong dimensional stability
- ✓Higher upfront budget than vinyl
Performance still depends on the whole window
Fiberglass frame properties are useful, but energy performance should still be checked on the NFRC label for the specific glass and frame configuration you plan to buy.
Use the numbers
Turn benchmarks into a project range
Change window count, frame material, style and location in the estimator. It returns a planning range and shows the assumptions instead of hiding them.
Open the cost calculator →Continue your research