Emergency adu — 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

When unexpected life changes happen, like an aging parent needing immediate care or a sudden lack of housing, an emergency ADU provides a functional solution. This service involves fast-tracking the planning and permitting phase to prioritize your build for urgent occupancy. You need this if you require a secondary living space on your property quickly to address a critical housing shortage for family members, ensuring they have a safe, private, and independent place to stay without waiting for standard construction timelines.

Frequently asked in San Mateo

Also serving nearby: Hayward · Daly City · Oakland · Sunnyvale · Fremont

All cities in California →

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, Hillsborough, Parkside, Shoreview — and every surrounding area.