Pocket replacement (new window sash and glazing into existing frame), standard double-hung or casement, vinyl, double-pane low-e/argon: $400–$800 per window including installation. Full-frame replacement (complete removal, rough opening prep and any framing repair, new window, interior trim) in multi-chamber vinyl: $600–$1,400 per window; fiberglass: $900–$2,000. Specialty shapes, large pictures or picture/casement combinations, or custom sizes: $1,200–$3,500+. Whole-house full-frame replacement on a 2,000 sq ft home with 14–18 windows: $8,000–$22,000 in vinyl, $12,000–$32,000 in fiberglass. Budget-driven window projects often become more expensive than expected when framing moisture damage is discovered on the opening — a risk that increases with every year a poorly flashed window remains in the wall.