Goal: The homeowner wanted to convert an existing structure into a small backyard ADU for extra space for their family.

Design Challenge: The homeowners wanted to convert their existing detached garage into an ADU for added space for guests and family, but the city required the preservation of the majority of the century-old garage's framing. This limited the final size of the ADU to match the footprint of the historic structure.


Process and Solution: The homeowner had a clear vision of the floorplan and style they wanted for their ADU. The city required preserving the majority of the existing structure which meant that most of the original framing had to stay. The homeowner wanted large, double glass doors which meant that the new opening required additional support and specialized framing.

Housable designers suggested portal framing to support the structure and meet the municipal requirements while satisfying the homeowners desire for an open, airy, and bright space. The final ADU design included a 10’x16’ studio, a kitchenette, and a bathroom with a shower.

This project was completed in 18 months and cost of $165,000, $2,975 of which was for Housable feasibility and drafting services, which saved the homeowner over $10,000 based on the going rate for architectural services.


Unique Project Traits:

• The municipality required the preservation of the original 100-year-old structure


• Portal framing was used to support the integrity of the orginal Model-T garage


• Stormwater had to be directed away from the neighboring lots