San Ramon, Contra Costa County

ADU / Guest House Cost in San Ramon, CA

San Ramon remodeling costs are 15% abovethe California state average. Here's what a typical adu / guest house costs in San Ramon in 2026, based on a 500 sqf project.

Budget

$143,750

$288/sqf

Mid-Range

$230,000

$460/sqf

High-End

$345,000

$690/sqf

Cost breakdown

Foundation & Framing

25%$57,500

Mechanical (HVAC, Plumbing, Electrical)

20%$46,000

Interior Finishes

20%$46,000

Exterior & Roofing

15%$34,500

Kitchen & Bath Fixtures

10%$23,000

Permits, Plans & Engineering

10%$23,000

Breakdown based on mid-range estimate of $230,000

Typical Timeline

4-8 months

Permits Required

Building, electrical, plumbing, mechanical. May require plan check.

Remodeling in San Ramon

Affluent Tri-Valley suburb with newer homes (1980s-2000s). Remodels tend to be kitchen upgrades and master bathroom expansions. HOA restrictions may limit exterior modifications.

California allows ADUs on most residential lots since 2020. An ADU adds living space and rental income. Cities must approve or deny within 60 days of a complete application.

Have estimates for your San Ramon project?

Upload them and get an AI-powered comparison with CSLB license verification. Free.

Compare Estimates →