Naperville is a high cost-of-living market — pricing guide and permit rules below.
Naperville window replacement rates: $4,000-$14,000 per system. Always get 3 written quotes and verify IL licensing at Illinois IDFPR (idfpr.illinois.gov). Sales tax on materials: 10.25%.
Naperville requires permits when work exceeds $500 or involves full system replacement. Your licensed contractor pulls the permit — if they ask you to pull it, that's a red flag.