Adu building — San Mateo, CA
Last updated: September 24, 2026
What affects the price
Building an ADU involves several moving parts that shape your total budget. The biggest factor is whether you choose a prefabricated unit or a custom build on-site. Site preparation is also significant; if your land requires extensive grading, utility trenching, or foundation work, costs will climb. Your choice of finishes—like kitchen cabinetry, flooring, and siding materials—also shifts the bottom line. We help you navigate these variables to find a setup that fits your property. Exact pricing confirmed free on the call.
About this service
Frequently asked in San Mateo
What are common questions about backyard accessory dwelling units in San Mateo?
Homeowners in San Mateo often ask about the process for building a backyard ADU. They want to know how it impacts their property value and what local regulations apply. Many inquire about the typical timeline for construction and the potential for rental income. Understanding the different types of ADUs available is also a frequent topic. These questions are best answered by a local expert who can provide accurate, city-specific information. Call us to get your questions answered directly.
How do I get an ADU quote in San Mateo?
Are there emergency ADU services in San Mateo?
Where can I find accessory dwelling unit builders near me in San Mateo?
What is the cost to build an accessory dwelling unit in San Mateo?
What are accessory dwelling units (ADUs)?
What are homes with mother-in-law suites like?
Also serving nearby: Hayward · Daly City · Oakland · Sunnyvale · Fremont
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of San Mateo — population 101,327; about 8,350 residents per square mile across 12.1 sq mi. ZIP codes covered include 94401, 94402, 94403, 94404, 94497.
Neighborhoods served in San Mateo: Bay Meadows, Edgewater, Laurel Creek, Marinship, Peninsula Point, Shoreview — and every surrounding area.
Areas we serve
Browse by state, then city.
California (4)
All of California · Rialto · San Buenaventura (Ventura) · San Mateo · Vacaville