Vinyl or fiberglass windows — which is better?

Vinyl is the better value for most US homeowners — lower cost ($400–$800/window installed), 25–30 year lifespan, ENERGY STAR-qualifying options across the price range. Fiberglass costs 40–80% more ($700–$1,400/window) but lasts 30–50 years, holds paint indefinitely, and resists thermal expansion better in extreme climates (think Phoenix summers or Minnesota winters). Wood is highest-end at $900–$2,500/window with 30+ year life but requires periodic refinishing. Aluminum is the worst thermal performer and is largely retired from US residential except in coastal high-wind zones. For a typical 12-window swap, vinyl saves $4,000–$8,000 over fiberglass.