Northwest ADU Bellevue

Northwest ADU is a full-service ADU design, permitting, and construction company specializing exclusively in accessory dwelling units throughout Western Washington. The company was created to focus specifically on ADU projects and is backed by the construction expertise of Northwest BNR. Its services cover the process from feasibility and design through permitting, construction, final inspection, and handover.

An accessory dwelling unit (ADU) — also known as a granny flat, in-law suite, backyard cottage, casita, or secondary dwelling unit — is an independent living space located on the same property as a primary residence.

ADU Services

1. Detached ADUs: Northwest ADU designs and builds standalone backyard homes that can be used for rental income, family housing, guest accommodation, home offices, or future downsizing.
2. Garage Conversions: Existing garages can be converted into fully functional, code-compliant residential living spaces.
3. Basement Conversions: Underused basement space can be converted into apartment-style living areas where local regulations permit.
4. Build-Ready ADU Plans: The company offers pre-designed, permit-ready ADU plans intended to streamline the design and approval process.

What Northwest ADU Offers Beyond Construction

Northwest ADU manages the ADU project through a coordinated process beginning with site feasibility and consultation, followed by design and planning, permitting, construction, and final inspection. During feasibility, the company evaluates factors such as lot size, zoning, setbacks, height limits, utility capacity, stormwater requirements, access, and grading conditions.

Its design and planning stage includes floor plans, budgeting, and engineering, while the permitting phase involves handling city approvals and required documentation. Construction is presented as a licensed, insured, quality-controlled process through final inspection and handover.

Northwest ADU also offers several build-ready detached ADU configurations, including studio units of approximately 400–600 square feet, one-bedroom units of 600–800 square feet, and two-bedroom units of 800–1,000+ square feet, subject to local requirements.