160 West 77th Street is a residential cooperative built in 1925 and has 38 apartments. Located in the Upper West Side / Central Park West Historic District, the building had failing double hung replacement windows which were no longer functioning. Our goal was to design historically accurate aluminum and insulating glass windows based on archival research. We determined the original painted wood window color and the window configuration to be 6 over 1. We provided professional guidance and oversight throughout the project from initial research, design development, construction documentation and administration. Field surveys included photographic documentation and identification of each window for each apartment. All windows were custom made with aluminum extrusions and insulating glass units. Aluminum window frame profiles including muntins were fabricated to match existing original window profiles and historically matching color. Our replacement window design program improved both the building façade and the lives of all residents at 160 West 77th Street.