ADU & DADU Builder

Accessory dwelling units are the smartest square footage you can add — rental income, multi-generational living, or a home office in the backyard. We design, permit, and build attached ADUs, detached ADUs (DADUs), and garages, navigating the zoning rules that change block to block.

ADU rules in Washington cities are a moving target — setbacks, height, parking, and owner-occupancy vary by jurisdiction. Because we handle design and permitting in-house, we know what each city will approve before we draw it. We build the ADU as a complete small home: foundation, mechanical, and finishes, ready to rent or move into.

What's included

• Attached and detached ADUs (DADUs)

  Attached ADUs inside or on the main house and detached ADUs (DADUs, backyard cottages) built from the foundation up as complete small homes.

• Garage conversions and new garages

  Converting an existing garage into living space, or building a new detached garage — with or without a workshop or living space above.

• Zoning and setback analysis

  Before we draw, we check what your city allows on your parcel: setbacks, height, lot coverage, parking and owner-occupancy rules that change block to block.

• Design, engineering, and permitting

  Architectural plans, structural engineering, land-use review and the building permit are produced and carried by our in-house team.

• Full mechanical and finish build-out

  Foundation, framing, roof, plumbing, HVAC and electrical, insulation, drywall, cabinets, tile and flooring — a finished unit ready to rent or move into.

• Utility connections and separate metering

  Water, sewer and power connections to the unit, shared with the main house or separately metered when the city or your plans call for it.

How it works

1. 1
   Free advice visit

   We walk the yard or garage, confirm the zoning basics for your parcel and talk through attached, detached or conversion — then leave you a scoped range.

2. 2
   Complimentary 3D model

   The unit on your actual lot: footprint, height, windows and how it sits relative to the main house and the neighbors.

3. 3
   Design, engineering and land-use check

   Construction drawings and stamped engineering, with the setback, height and coverage analysis documented for the permit.

4. 4
   Permits

   Building, trade and land-use permits submitted and tracked by our office, including the utility and impact-fee paperwork.

5. 5
   Build

   Foundation to finishes by one crew, with utility connections or separate meters coordinated with the city and the utility district.

6. 6
   Final walkthrough

   Final inspections, certificate of occupancy where required, and a walk through the finished unit.

The same ten-step process runs every project we build — see how we work.

What it costs

A detached new unit is the baseline; an attached ADU runs about 8% less and a garage conversion about 20% less in our estimate tool because the shell already exists. Size, a second story or over-garage design, separate meters, a full kitchen versus a kitchenette and the finish level move the range; utility connections, impact and connection fees, and design and permit fees are priced separately.

Timeline

1. Zoning check, design and 3D model

   What the city allows on your parcel, then the unit drawn and modeled on your lot.

2. Engineering and permits

   Stamped drawings, land-use review and the building permit — the part that varies most by city.

3. Foundation, framing and envelope

   The unit is dried in: slab or stem walls, framing, roof, windows, siding.

4. Utilities, rough-ins and inspections

   Water, sewer and power to the unit, then plumbing, HVAC and electrical rough-ins inspected before drywall.

5. Finishes and move-in

   Kitchen or kitchenette, bath, flooring, paint and fixtures, then final inspection. Our 680 sq ft Meridian DADU was built in 4 months from the foundation up.

Permits and codes