Accessory Dwelling Unit
2605 Sonoma Blvd.
Vallejo, CA
Background
Built in 1908, this two-story, mixed-use building contained two apartments on the upper floor and a ground-floor commercial unit. A fire at the rear of the property prompted the owner to address long-standing issues resulting from decades of piecemeal additions and makeshift repairs. Among the problems were:
Along with addressing the existing deficiencies, the owner hoped to convert one of the apartments into an Accessory Dwelling Unit (ADU). This project was turned away by other architects who considered the project too risky, but we found an optimal solution.
Approach
We worked with the owner, a land surveyor, and the city’s chief building official to navigate the legal and structural hurdles confronting the project. Since a lot-line adjustment was not feasible in this case, attention shifted to relocating structures from property lines to meet setback requirements. Working within space limitations and restrictive building code requirements,we designed two units that integrated skylights as a design-forward solution to meet daylighting and ventilation requirements. The biggest challenge was integrating new construction into a 115-year-old building with a minimal foundation. Our design removes the compromised middle portion of the structure entirely to rebuild it with proper foundation walls and seismic bracing. This new structural core ties existing wings together while providing the stability and longevity the original structure lacked.
Built in 1908, this two-story, mixed-use building contained two apartments on the upper floor and a ground-floor commercial unit. A fire at the rear of the property prompted the owner to address long-standing issues resulting from decades of piecemeal additions and makeshift repairs. Among the problems were:
- sections of the structure and exterior stairs extended beyond the property line
- four uneven ground-floor levels in a single unit
- widespread substandard construction
Along with addressing the existing deficiencies, the owner hoped to convert one of the apartments into an Accessory Dwelling Unit (ADU). This project was turned away by other architects who considered the project too risky, but we found an optimal solution.
Approach
We worked with the owner, a land surveyor, and the city’s chief building official to navigate the legal and structural hurdles confronting the project. Since a lot-line adjustment was not feasible in this case, attention shifted to relocating structures from property lines to meet setback requirements. Working within space limitations and restrictive building code requirements,we designed two units that integrated skylights as a design-forward solution to meet daylighting and ventilation requirements. The biggest challenge was integrating new construction into a 115-year-old building with a minimal foundation. Our design removes the compromised middle portion of the structure entirely to rebuild it with proper foundation walls and seismic bracing. This new structural core ties existing wings together while providing the stability and longevity the original structure lacked.
