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Golden Ridge Construction is a licensed general contractor (License #1149928) serving San Mateo County, California, in San Mateo County. We handle kitchen and bathroom remodels, ADUs, home additions, and whole-home remodels across San Mateo County.
These are planning ranges for typical 2026 projects, not quotes. Every project is priced after a site visit.
Construction and remodeling in San Mateo County spans a wider range of housing than its size suggests. Burlingame and Hillsborough carry period homes from the 1910s to the 1930s; San Bruno, Millbrae, San Carlos and Belmont are largely post-war; Foster City is built on engineered fill from the 1960s onward; and Pacifica and the Midcoast face weather no inland city deals with.
What most of the county shares is age and salt air. Original single-pane windows, uninsulated walls and undersized electrical panels are the norm, and anything within a few miles of the ocean pays a price in corrosion and moisture that inland homes never do.
There is no single San Mateo County building permit process. Each city runs its own building department, and the unincorporated areas — North Fair Oaks, Emerald Lake Hills, the Midcoast and others — go through the County Planning and Building Department instead. The coast adds a layer nowhere else on the Peninsula has.
The coastal rule is the one that catches people out. Under the County's Local Coastal Program the urban Midcoast — Montara, Moss Beach, El Granada, Princeton — is limited to 40 housing unit building permits a year including ADUs, and the County has reported it cannot accept applications for new residential units there until January 1, 2028 unless the plan is amended sooner. If you are on the coast, confirm the current status before you design anything.
Permit fees and review times change. Check current requirements on the County of San Mateo Planning and Building Department building permits page before planning around a date.
Opening the kitchen to the living space is the change that most transforms a post-war plan, and it is structural work because that wall is usually load-bearing. Adding a second bathroom inside the existing footprint changes daily life more than square footage does.
On the coast and in the fog belt, exterior envelope work carries more weight than it does elsewhere: windows, flashing, siding and drainage. Deferred maintenance compounds faster here.
North Fair Oaks, Emerald Lake Hills, Devonshire, the Sequoia Tract and the coastal communities are not inside any city. Those properties permit through the County of San Mateo Planning and Building Department, with its own zoning regulations and review process.
Two extra reviews apply in specific places. Projects in North Fair Oaks go before the North Fair Oaks Community Council, and Midcoast projects go before the Midcoast Community Council. Neither is a formality, and both add calendar time that belongs in your schedule from the start.
The County also splits its ADU rules in two: one chapter for ADUs outside the Coastal Zone and a separate one for ADUs inside it. Which chapter applies to you is not a detail — it changes what is allowed.
Plenty of San Mateo County homes have a converted garage or back unit that was never permitted. Since January 2025, California's AB 2533 has offered an amnesty path for ADUs and junior ADUs built without permits before January 1, 2020.
A local agency cannot deny that permit purely because the unit fails current building code, unless the problem is a genuine health or safety hazard, and no impact fees or utility connection charges apply unless upgrades are needed for safety. It matters most at sale, because unpermitted square footage does not appraise. Our [garage conversion guide](/projects/garage-conversion-bay-area-options) covers the work itself.
State law sets the floor everywhere in the county: ministerial review within 60 days for designs meeting objective standards, and no owner-occupancy requirement since 2024. Lots in the bayside cities are generally regular and often deep enough for a compact detached unit.
The Coastal Zone is the exception to everything above. Inside it, an ADU is subject to the coastal chapter of the County's rules and the Midcoast permit cap, so the usual state timelines are not the whole story.
Call (408) 418-8376 or visit our contact page for a free, no-obligation estimate, explore our services, and see all service areas we cover.