In response to a request from the City of Cotati, Interactive Resources prepared a study for the assessment of the window units at two city facilities — City Hall and the adjoining Community Center. Both facilities were originally constructed as elementary schools, the former in 1938, the latter in 1959. Windows at both were beyond their expected service life and thermally inefficient.

The Community Center had retained its original single-glazed aluminum windows. Hardware at several units was in disrepair and non-functional. The study recommended the replacement of these window units with thermally efficient, PVC replacement units.

The south-facing windows at City Hall provided poor acoustical separation for city offices from the adjoining busy thoroughfare and appeared to be badly weathered. Although the original wood sash had been replaced with an aluminum retrofit unit in the 1980s, these units were aging, and the surrounding wood frame and trim were deteriorated and weathered. Visual observations and destructive testing revealed a potential source of water penetration into the building due to open joints between the deteriorated wood trim and adjoining cement plaster walls; complete deterioration of the original 30# felt window flashing was observed at one key location. The study recommended the removal of all south-facing windows and replacement with a durable, double-glazed fiberglass window system to meet both thermal and acoustical requirements as well as providing compatible match with the building’s original character.

The submitted study was approved by the city and construction documents were prepared for the window replacement. Construction was completed in 2023. The improvement in the buildings’ appearance and performance related to the window replacement project has been well received by the city, particularly the positive impact to the acoustical quality of the City Hall office spaces.