Compare vetted ADU builders—fast & fair
Add space and income with confidence
ADU Construction in Seattle helps you unlock flexible, high-value space on the same lot as your primary residence. An accessory dwelling unit can create additional living space for aging parents, adult children, or visiting family as an in law suite or granny flat. It can also generate rental income and increase property value.
Whether you want a guest house, basement apartment, or carriage house, our vetted ADU construction contractors align your project with local zoning regulations and building codes.
We guide feasibility, site work, utility connections, and permits so your additional dwelling unit is compliant and move in ready. Works for many single family home properties and select manufactured home sites. Start with a quick estimate and compare proposals today.
Choose the right ADU for your lot
Every lot is different. We compare ADU Construction options in Seattle so you can pick the accessory dwelling unit that fits space, budget, and codes. See costs, timelines, and compliance for detached ADUs, internal ADUs, and garage conversion carriage houses.
Build a new additional dwelling unit on your existing property. Great for rental income and privacy. We review site conditions, site work, utility connections, drainage lines, setbacks, and permits so your detached ADU is code compliant and move in ready.
Convert existing space inside the primary residence, like a basement apartment. Often the most cost effective. We plan separate entrance, square footage, egress, utility tie ins, and local building codes so your accessory dwelling unit meets Seattle rules.
Turn a detached garage into an ADU or add a carriage house above. We handle architectural plans, structural changes, parking and egress needs, utility connections, and zoning laws. Create flexible living area for family or rental income with full compliance.
Four Steps to a Great Remodel
Complete a 60-second form. We verify license, insurance, and track record, then introduce 2–3 contractors matched to your scope, budget, and schedule.
Tell us your scope, timeline, and budget: kitchen remodeling, bathroom remodel, whole house remodeling, painting, flooring, or a full design-build plan. Serving the Seattle metro area from Phinney Ridge to Mercer Island.
We verify license, insurance, and local track record. Then we introduce 2–3 qualified general contractors that fit your style, schedule, and price range, clean crews with proven quality work and recent projects.
Get structured, apples-to-apples bids with scope, materials, timeline, and warranties lined up. Our team acts like friendly project managers—answering questions, flagging gaps, and helping you choose the best value.
Book a site visit, confirm details, and set milestones. We stay available through contract and start of construction so your dream home plan stays on track for your whole family.
Start smart with expert guidance
An accessory dwelling unit is a self-contained home on the same lot as your primary residence. In Seattle it can be a detached ADU, an attached ADU, or an internal ADU. Homeowners use ADUs for aging parents, adult children, guest house space, or dependable rental income.
Costs vary by size, site work, drainage lines, utility connections, and finishes. Detached ADUs generally cost more than internal conversions. Request side-by-side proposals from vetted ADU construction contractors to compare scopes, allowances, and timelines before you commit.
Yes. ADU projects require building permits and must meet local building codes and zoning regulations for setbacks, height, parking, egress, and separate entrance. Your matched ADU construction company handles obtaining permits, architectural plans, inspections, and final approvals.
Most single family home lots in Seattle can host one or more of the following: detached ADU, attached ADU addition, or internal ADU such as a basement apartment. Feasibility depends on lot coverage, utilities, and local zoning rules. Start with a quick address check.
Typical timelines include feasibility and design, permitting, and on site construction. Internal ADUs can be faster. Detached ADUs add site preparation, utility connections, and concrete work. Plan several months from design to final inspections and move in ready status.
Long-term rentals are common and can offset construction costs and financing. Short-term rentals may have restrictions. Always confirm local regulations and property taxes. Ask matched pros for rent comps and operating cost assumptions you can review with a CPA.
Many homeowners use renovation loans, HELOCs, or cash-out refinance. Lenders consider construction costs, equity, and potential rental income. A qualified ADU construction company can supply plans and budgets lenders need for underwriting.
A complete scope usually covers ADU design, architectural plans, structural work, separate entrance, insulation, windows, plumbing and installing water supply, electrical, HVAC, sewer tie-ins, and finishes. Pros also manage site work, utility connections, and final inspections.
More space and income, less hassle
Unsure about ADU construction costs, financing options, or site conditions? Get a free feasibility check and 2 to 3 contractor proposals. Compare apples to apples on scope and schedule. Tap Get Started now and make your ADU move in ready.