Adu builder — 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
An ADU builder is a professional team that handles the design, permitting, and physical construction of your secondary dwelling. Hiring a specialist is important because they understand the specific zoning codes and structural requirements unique to small homes. You should hire an ADU builder early in the process to ensure your design is feasible and stays within your budget. Factors like custom features and site slope can change your final investment. Exact pricing confirmed free on the call.
Frequently asked in Hillsboro
What are the best ADU services in Hillsboro?
Are emergency ADU services available in Hillsboro?
What are homes with mother-in-law suites like in Hillsboro?
Homes with mother-in-law suites in Hillsboro are typically single-family residences that include an attached or detached secondary dwelling unit. These suites are designed to offer independent living quarters, complete with a bedroom, bathroom, and kitchenette, ensuring privacy and convenience for extended family members. We can help you design and build such suites on your property.
What are the requirements for an Accessory Dwelling Unit contractor in San Diego?
While this question refers to San Diego, for Hillsboro, Oregon, an ADU contractor must be licensed by the state of Oregon and possess appropriate insurance. They should have a proven history of ADU construction and a thorough understanding of Hillsboro's municipal codes and zoning ordinances. We ensure that the professionals we work with meet these stringent local requirements.
What is a prefab ADU in Hillsboro?
A prefab ADU in Hillsboro is a dwelling unit manufactured off-site in a controlled factory environment and then transported to the property for assembly. These units must comply with all Oregon state building codes and Hillsboro's specific land use regulations. Prefabricated ADUs can offer advantages in terms of construction speed and quality consistency. We can evaluate their suitability for your project.
What is the process for an Accessory Dwelling Unit permit in Hillsboro?
The ADU permit process in Hillsboro involves submitting detailed plans to the city's planning and building departments for review. These plans must demonstrate compliance with all local zoning ordinances, including setbacks, height restrictions, and lot coverage limits. Once approved, construction can commence, followed by required inspections. We facilitate this entire permitting journey.
What is the Accessory Dwelling Unit cost in Hillsboro?
The accessory dwelling unit cost in Hillsboro varies significantly based on the ADU's size, design complexity, chosen materials, and any necessary site preparation or utility upgrades. Local labor rates and material availability also play a role. We provide detailed, customized quotes after a thorough site assessment to give you an accurate financial projection.
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: Glencoe, Brookwood, Edyville, Raleighwood, Jackson School Area, North Plains — and every surrounding area.
Areas we serve
Browse by state, then city.