ADU Construction Services by Deane Home Services
Deane Home Services is a general contractor based in South King County, Washington, specializing in the design and construction of Accessory Dwelling Units (ADUs). They serve homeowners across cities including Kent, Des Moines, SeaTac, Tukwila, Federal Way, Renton, and Auburn. As a family-owned and operated business, they are fully licensed, bonded, and insured.
An ADU can serve a range of purposes — housing aging parents, providing a dedicated home office, or generating rental income. Deane Home Services approaches each project with attention to the specific constraints of the lot and the homeowner's financial goals, rather than offering a one-size-fits-all solution.
Their ADU services cover several distinct project types:
- Garage Conversion: Existing garages often provide a practical starting point for a livable space. Deane Home Services handles insulation, leveling, utility trenching, and all work required to bring the structure up to code as a habitable dwelling unit.
- Attached ADUs and Basement Remodeling: For homeowners looking to keep family close while maintaining privacy, they convert underutilized interior spaces into fully permitted dwelling units. This includes basement apartments with proper egress and fire separation, as well as bump-out additions that create a dedicated in-law suite with its own exterior entry.
- Detached ADUs and Backyard Cottages: A detached ADU (DADU) offers complete independence from the main house. Deane Home Services builds standalone backyard cottages that include full kitchens and bathrooms, vaulted ceilings, and private entrances with patios — suitable for use as a granny flat, casita, or rental unit.
Design Approach and Space Planning
Deane Home Services places emphasis on architectural cohesion. Their goal is for a new ADU to look as though it belongs on the property rather than being an afterthought. This involves matching exterior siding, roof pitch, and paint colors to the main home. Window and entryway placement is also considered carefully to maintain privacy for both the primary residence and the accessory unit.
Inside, their floor plans are designed to make the most of smaller square footage. Strategies include built-in storage solutions and open layouts that prioritize natural light and clear sightlines. For attached additions and interior remodels, they also focus on seamless transitions — matching flooring, millwork, trim, and HVAC systems so that new spaces feel consistent with the rest of the home.
For detached and attached ADU projects alike, interior finishes are selected to support both livability and long-term rental appeal.
Permitting, Zoning, and Project Management
ADU construction in Washington State involves navigating detailed zoning codes that vary by municipality. Setback requirements, lot coverage limits, parking rules, and owner-occupancy conditions differ from city to city. Deane Home Services conducts feasibility studies and zoning analyses specific to each property address before design work begins. They have experience working within the regulatory frameworks of cities such as SeaTac, Renton, and Normandy Park.
Utility connections are another significant factor in ADU projects. Connecting a new structure to existing sewer, water, and electrical systems requires careful planning and civil work. Deane Home Services manages this process directly, assessing early in the project whether a new dedicated connection to the street is required or whether tying into the main home's existing lines is feasible.
In terms of timeline, a typical custom ADU construction project takes between four and seven months, depending on site access and utility complexity. The permitting process can add additional time prior to breaking ground. Deane Home Services manages the full project timeline and communicates city processing updates to homeowners throughout.
They also provide guidance on budget allocation, helping homeowners understand where investment is most likely to yield returns — whether through rental income potential or increased property value.
Deane Home Services serves homeowners throughout South King County and surrounding communities, bringing the same approach to craftsmanship and project management to each ADU build they undertake.
