Seattle 3-Home Infill

Location: Central District of Seattle, Washington

Unit Type: Primary Residence, Attached Accessory Dwelling Unit (AADU), Detached Accessory Dwelling Unit (DADU)

Design Goals: Located in Seattle’s Central District, this project reimagined an existing single-family property into a carefully designed three-home urban compound. H2D worked closely with the homeowners and builder to maximize the site’s potential while creating distinct yet cohesive living spaces that support multi-generational living, rental flexibility, and long-term urban density. The project involved lifting the existing two-story home to construct a new full height basement, allowing for the addition of a spacious attached accessory dwelling unit (AADU) below the primary residence. Together with a new detached accessory dwelling unit (DADU) in the rear yard, the property now accommodates three independent dwelling units carefully integrated across the site. H2D’s design focused on balancing density with livability, bringing natural light, privacy, and efficient circulation to each home. The new basement-level AADU includes three bedrooms, a full bathroom, kitchen, living area, laundry, and a separate exterior entrance, creating a comfortable and independent living space under the footprint of the existing home. At the rear of the property, the new two-story DADU was designed as a compact yet highly functional detached residence. The main level features an open-concept living, dining, and kitchen space with integrated storage and a covered entry, while the upper floor contains two bedrooms, a bathroom, and laundry. Clean lines, efficient planning, and carefully considered scale allow the new structure to complement the existing home while contributing to the evolving urban fabric of the neighborhood.

Style: Transitional

Design Challenges + Site Constraints: One of the primary design challenges for this project was thoughtfully integrating three independent dwelling units onto a compact urban lot while maintaining functionality, privacy, and access to outdoor space. The design required careful coordination between zoning constraints, height limitations, and the realities of working within an already developed residential site. Because the existing house was lifted to accommodate the new basement-level AADU, H2D worked closely within Seattle’s height restrictions to ensure the revised structure remained compliant while still providing comfortable ceiling heights and livable interior spaces. Particular attention was given to the existing front porch, portions of which were non-conforming to current zoning setbacks. The porch and entry sequence were carefully redesigned during the lift to bring the project into compliance while preserving the character and proportions of the original home. In the rear yard, fitting a new detached accessory dwelling unit (DADU) into an already petite site presented an additional challenge. The design needed to balance required setbacks, access, circulation paths, and clearances while still preserving usable outdoor living space for all three homes.

Team:
+ Architecture: H2D Architecture + Design
+ Build: Crescent Builds
+ Photography: Anastasiya Homes