Prefab adu — Hillsboro, OR
Last updated: September 24, 2026
What affects the price
Building an ADU is a custom project, so costs vary based on your specific choices. Site conditions are the biggest factor; if your land requires significant grading, utility extensions, or foundation work, those expenses add up quickly. Choosing high-end finishes, custom cabinetry, or complex roof lines will also push the budget higher compared to a standard design. Prefabricated units often offer predictable costs, while custom site-built structures allow for more flexibility but can be harder to estimate upfront. Exact pricing confirmed free on the call.
About this service
A prefab ADU is a unit constructed off-site in a controlled factory environment before being delivered and assembled on your property. You might choose this option if you want a faster construction timeline and less disruption to your yard compared to traditional building methods. Once the foundation is ready, the structure is dropped into place and connected to utilities. It is an efficient way to add housing while maintaining high quality control standards throughout the entire manufacturing process.
Frequently asked in Hillsboro
What are the regulations for accessory dwelling unit rental in Hillsboro?
Can you provide an ADU quote for my Hillsboro property?
What is the process for an accessory dwelling unit permit in Hillsboro?
How do I find a qualified ADU builder in Hillsboro?
What is the accessory dwelling unit permit cost in Hillsboro?
What are the options for ADU housing in Hillsboro?
What is the estimated accessory dwelling unit construction cost in Hillsboro?
Also serving nearby: Beaverton · Portland · Vancouver · Gresham · Salem
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Hillsboro — population 107,730; about 4,168 residents per square mile across 25.8 sq mi. ZIP codes covered include 97123, 97124, 97129.
Neighborhoods served in Hillsboro: Orenco Station, Brookwood, Downtown Hillsboro, South Hillsboro, Walnut Creek — and every surrounding area.
Areas we serve
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