History
Scope of Work
- Restoration of 5’ x 8’ oversize wood sash windows
- Some re-glazing with restoration glass
- Repair and reinforcement of sash components using Dutchman joinery and epoxy
- Upgraded hardware and weather stripping to enhance operability and insulation
Points of Interest
- Each 5’ x 8’ sash window was restored to full functionality while preserving historic details
- Ring sash lifts and poles were installed to allow easy operation of upper sashes
- Restoration glass and custom bronze interlocks enhanced both authenticity and performance
Challenges
- Managing the size and weight of oversize sash windows during removal and restoration
- Preserving intricate sash profiles and maintaining visual consistency with adjacent units
- Seamlessly integrating modern weather stripping into landmarks windows
Materials & Techniques
- Materials Used
Original hardwood sashes, restoration glass, custom bronze interlocks, brass hardware, Benjamin Moore exterior paint - Technique Used
Dutchman joinery, epoxy patching, re-glazing, precision hardware integration, complete painting - Tools Used
Traditional machinery, custom shaper blades, hand equipment, industrial painting equipment - Waterproofing
Bronze and brush weather stripping, concealed sealing systems - Installation Notes
All frames were restored in place while sashes were taken back to shop. Temporary boarding used while work was been completed. Reinstalled with reinforced sash weights and pulleys; system balanced to guarantee full operability
920 Fifth Avenue is an Italian palazzo-style co-op building designed by renowned architect J.E.R. Carpenter and completed in 1922. Carpenter himself lived in the building until his death, as did legendary actress Gloria Swanson. The building is located at the corner of 73rd Street and Fifth Avenue. It is a designated New York City Landmark. It is also one of the Upper East Side’s most iconic pre-war addresses.
Building Information
Type of Building: Historic Landmark Residential (Co-op)
Location: 920 Fifth Avenue, New York, NY
Year Built: 1922
Architect: J.E.R. Carpenter
Why the Work Was Needed
The penthouse windows overlooking Central Park had deteriorated over time, compromising both functionality and thermal performance. These oversized, eight-over-eight wood sash windows required careful restoration to preserve their historic character while improving usability and energy efficiency.
What We Did
Each sash was stripped to bare wood, revealing the original profiles which were carefully preserved. All existing putty was removed, and the sashes were re-glazed using restoration glass to maintain visual authenticity.
Where rot was found, we used Dutchman joinery techniques and marine-grade epoxy to restore structural integrity. We installed custom-fabricated pulleys. We also fitted the windows with maximum load-bearing sash chains. These upgrades accommodate the weight of the large sashes.
To improve thermal performance without altering appearance, we added bronze interlock weather stripping and concealed modern brush seals. Hardware upgrades included brass adjusters, replacement sash locks to match the originals, and ring sash lifts. A sash pole was also added to the tallest windows for safe and easy operation of the upper sashes.
The Result
The restored windows now combine 1920s craftsmanship with 21st-century performance—maintaining the building’s architectural integrity while enhancing comfort and usability. From the street, the penthouse façade remains unchanged. Inside, residents enjoy clear views. They also experience balanced operation and improved insulation. This is achieved through discreet restoration and authentic materials.
At Right Path Windows & Doors, projects like this reinforce our guiding principle: preserve, not replace. By restoring J.E.R. Carpenter’s original design with precision and respect, we ensure that the elegance of Fifth Avenue continues to endure for generations.
📞 Call or text (914) 200-4481 to discuss your next restoration project.