Homes with 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 in-law suites feature a dedicated area for aging parents or guests, usually with a bedroom and bathroom. You need this if you are managing multi-generational living and want to provide privacy for family members while staying close by. Exact pricing confirmed free on the call.
Frequently asked in Federal Way
What are prefabricated accessory dwelling units in Federal Way?
Are modular accessory dwelling units a good option in Federal Way?
What is the cost to build an accessory dwelling unit in Federal Way?
Are there emergency ADU options in Federal Way?
What is an ADU unit in Federal Way?
What are the general guidelines for accessory dwelling units (ADUs) in Federal Way?
What ADU services are available 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, Lake Kilo — and every surrounding area.
Areas we serve
Browse by state, then city.