Homes with mother in law suites — Federal Way, WA
Last updated: September 24, 2026
What affects the price
Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.
About this service
Homes with mother-in-law suites provide a private space for relatives to live comfortably on your property. You need this if you are planning to help family members transition to a more supportive living arrangement without sacrificing independence. These suites often include a small kitchenette and private entrance. Exact pricing confirmed free on the call.
Frequently asked in Federal Way
What's the ADU permit process in Federal Way?
Can you help me find accessory dwelling unit services in Federal Way?
Where can I find accessory dwelling unit builders in Federal Way?
I need an ADU estimate in Federal Way.
What are the requirements for an accessory dwelling unit rental in Federal Way?
What does 'accessory dwelling unit' mean in Federal Way?
In Federal Way, an 'accessory dwelling unit' (ADU) is a secondary housing unit on a single-family lot, like a backyard cottage or a converted garage. Licensed builders construct these units to provide extra living space, rental income, or housing for family members. They are designed to complement your main residence and adhere to local codes.
Are there accessory dwelling unit financing options in Federal Way?
Also serving nearby: Tacoma · Kent · Renton · Seattle · Bellevue
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Federal Way — population 97,701; about 4,375 residents per square mile across 22.3 sq mi. ZIP codes covered include 98003, 98023, 98063, 98093.
Neighborhoods served in Federal Way: The Commons, Mirror Lake, Woodmont, Star Lake, Allen's Creek — and every surrounding area.
Areas we serve
Browse by state, then city.