ADU Construction
Attached or detached accessory dwelling projects, subject to parcel feasibility and project review.
Plan the scope →selected Puget Sound communities
Adu and addition site planning
Access, utilities, drainage, and the existing house shape what can be built. Prepare a parcel-specific project discussion for selected King, Snohomish, and Pierce County locations.
Home Additions
New living space with the existing-house connection and site work included in the scope discussion.
Plan the scope →Garage Construction
Garage and accessory-structure projects reviewed for intended use, access, and utilities.
Plan the scope →How to define the work
Start with the property address and parcel number. Confirm whether a city or county administers the application; a Seattle, Everett, or Tacoma mailing address alone is not enough. Ask for current guidance for your proposed project type. Keep the answer and source with your site notes instead of applying another city’s rules.
The first review confirms project fit. Design, engineering, specialist assessments, permits, material selections, and construction responsibilities should be identified in the proposed scope. Availability and a final price require review of the actual property.
Start with Snohomish County site feasibility
Locate the proposed ADU area, existing structures, access and known utilities. Establish the reviewing jurisdiction and which records are reliable. A generous yard or an online parcel map alone does not confirm that an ADU can be built.
Turn unknowns into assigned investigations
List setback, access, utility and drainage questions with the professional or authority needed for each. Separate measured information from assumptions. Keep feasibility, design, permit review and contractor pricing as different decisions rather than presenting a preliminary sketch as a build commitment.
Carry findings into a defined proposal
When comparing a project scope, show which site questions are resolved and which remain conditions or allowances. Identify who supplies the next drawings and investigations. Preserve the feasibility notes so a bid does not accidentally omit access or utility work.
ADU and addition site feasibility: the parcel before the plan
A floor plan does not establish that a structure fits your parcel. This guide helps you assemble a site brief before design and pricing. It does not determine permitted unit count, setbacks, or parcel eligibility.
Use the planning guide →Send your project details and include your location, priorities, and timing.