Window Replacement vs Repair — The $50 vs $400 Decision
Not every problem window needs a $400 replacement. Some fixes cost $15. Others are repair traps that cost more every year than replacing would have. Here's the decision tree.
Quick answer: Repair ($15–150/window): failed balance, worn weatherstripping, loose sash lock, single-pane glass replacement. Replace ($300–1,200): fogged double-pane (seal failure), rotted frame, persistent drafts, single-pane in a busy room. Fog between panes = replace the insulated glass unit or the window — the seal never reseals.
Repair wins (fix for $15–150)
- Sash won't stay open → balance replacement $30–60
- Drafty sash → weatherstripping $15–30
- Loose lock → sash lock $10–25
- Cracked single-pane glass → glass cut to size $50–100
- Sticking paint seal → cut free, re-caulk $20
Replace wins (repair is a trap)
- Fog between panes → sealed unit failed; replace IGU $150–300 or window $300+
- Rotted frame/sill → structural; repair costs approach replacement
- Persistent drafts despite weatherstripping → warped frame
- Single-pane in bedrooms/living rooms → comfort + noise + energy
- Painted-shut + crumbly wood + 50+ years old → done its time
The energy math
Replacing single-pane with double-pane low-E saves $125–465/window per year in heating/cooling (Energy Star data by region). A $400 window in a cold climate pays back in 2–4 years. The same window replacing an already-double-pane unit saves $25–100/year — 6–12 year payback. Energy savings justify replacement from single-pane, not from newer double-pane.
The phasing strategy
Whole-house replacements get 10–20% volume pricing, but phasing wins when budget-bound: replace worst-first (bedrooms in cold climates, west-facing in hot ones), repair the middle, leave the barely-functioning for next year's phase. Mixed houses are normal — matching the right fix to each window beats a uniform half-fix.