New ADU Construction in San Mateo, CA
Ground-up detached ADUs — full-service design, permitting, and construction on your San Mateo lot.
About Our New ADU Construction Service
A brand-new detached ADU is the highest-value way to add living space, rental income, or multigenerational housing to a San Mateo property. We handle the entire ground-up build: site evaluation, foundation, framing, utilities, and finishes. Whether you want a 400 sq ft studio or a 1,200 sq ft two-bedroom backyard home, we design to California's statewide ADU standards and San Mateo County requirements so your project sails through plan check. Every build includes energy-code-compliant insulation, its own kitchen and bath, and a private entrance.
What's Included
Our Process
Site & Feasibility
We evaluate your lot, setbacks, and utility access to confirm what size and layout of detached ADU your San Mateo property allows.
Design & Permits
Our team produces construction drawings and submits to the City of San Mateo / San Mateo County for plan check, handling every correction.
Construction
Licensed crews build the foundation, frame, MEP, and exterior, keeping the site clean and your household informed at every milestone.
Finish & Final
Interior finishes, fixtures, and appliances go in, we pass final inspection, and hand you a move-in-ready, permitted backyard home.
Why New ADU Construction Matters
- Adds significant property value and rental income
- Ideal for aging parents or adult children
- Ministerial (by-right) approval under California ADU law
- Independent, permitted living space
- Long-term equity on your existing lot
Frequently Asked Questions
How big can a detached ADU be in San Mateo?
Do I need a big backyard for a detached ADU?
Can I rent out a new ADU?
New ADU Construction Service Areas
We provide new adu construction across San Mateo and the Peninsula, including:
Get a Free Quote
Free on-site estimate
Starting at
$250,000
Turnkey detached ADU, based on size, site conditions, and finishes.
Duration
6 - 10 months
Warranty
1-year workmanship warranty
Other Services
Why Choose Us
- Licensed & Insured
- Satisfaction Guaranteed
- Free Estimates
- San Mateo Local
- Design-Permit-Build
- 1-Year Workmanship Warranty