Historic Window Restoration: What's Involved

Window restoration is a specialized process that repairs and upgrades historic windows while preserving their character. According to the National Park Service, proper restoration can make windows last another century.

The Restoration Process

According to NPS Preservation Brief #9:

Assessment

• Evaluate each window's condition
• Document with photos
• Identify repair needs by component
• Prioritize based on condition

Disassembly

• Carefully remove sashes from frame
• Remove hardware for cleaning/repair
• Take out glazing (if replacing)
• Label all components

Repair/Replacement

According to NPS, typical repairs include:

| Component | Common Issues | Repair Approach |
|-----------|---------------|-----------------|
| Wood frame | Rot, separation | Epoxy consolidation, Dutchman repairs |
| Sash | Rot, loose joints | Re-glue, reinforce, replace members |
| Glazing compound | Cracked, missing | Remove old, re-glaze |
| Hardware | Worn, broken | Clean/repair or period replacement |
| Glass | Broken | Salvage glass or period-appropriate replacement |

Weatherstripping

Adding modern weatherstripping dramatically improves air infiltration:

• Spring bronze (most durable)
• Vinyl or foam (less expensive)
• Fitted to sash meeting rails and jambs

Finishing

• Strip and repaint (lead-safe if applicable)
• Reinstall restored hardware
• Reinstall sashes
• Adjust operation

Cost Comparison

According to industry estimates:

| Approach | Typical Cost per Window |
|----------|------------------------|
| Full restoration | $350-800 |
| Restoration + storm | $500-1,100 |
| New custom wood replica | $800-2,000 |
| Standard replacement | $400-800 |

Restoration often costs less while preserving character.

DIY vs. Professional

According to National Trust guidance:

DIY-appropriate:

• Weatherstripping installation
• Simple hardware cleaning
• Paint touch-up
• Storm window installation

Professional recommended:

• Structural wood repair
• Reglazing
• Major rot repair
• Lead paint handling
• Sash weight/cord replacement

Finding Specialists

According to NPS, qualified window restoration specialists:

• Understand historic construction methods
• Have experience with period hardware
• Know proper repair materials
• Can match existing profiles if replacement needed
• Understand Secretary of Interior's Standards

The Bottom Line

Window restoration preserves character while improving performance. According to NPS, for truly historic homes, it's often the better choice both financially and aesthetically.

*For complete guidance, see: [Historic Window Restoration](/guides/historic-window-restoration)*