Santa Rosa, Sonoma County

ADU / Guest House Cost in Santa Rosa, CA

Santa Rosa remodeling costs are 10% abovethe California state average. Here's what a typical adu / guest house costs in Santa Rosa in 2026, based on a 500 sqf project.

Budget
$137,500
$275/sqf
Mid-Range
$220,000
$440/sqf
High-End
$330,000
$660/sqf

Cost breakdown

Foundation & Framing
25%$55,000
Mechanical (HVAC, Plumbing, Electrical)
20%$44,000
Interior Finishes
20%$44,000
Exterior & Roofing
15%$33,000
Kitchen & Bath Fixtures
10%$22,000
Permits, Plans & Engineering
10%$22,000

Breakdown based on mid-range estimate of $220,000

Typical Timeline
4-8 months
Permits Required

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

Remodeling in Santa Rosa

Post-wildfire rebuilding has driven up contractor demand and costs in Sonoma County. Fire-resistant materials and defensible space requirements add to project scope. Coffey Park rebuild created a massive contractor shortage.

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 Santa Rosa project?

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

Compare Estimates →

Other projects in Santa Rosa

Kitchen Remodel
$33,000 – $99,000
Bathroom Remodel
$16,500 – $52,800
Room Addition
$66,000 – $181,500
Roof Replacement
$13,750 – $41,250
Exterior Paint
$5,500 – $19,250
Whole House Remodel
$297,000 – $990,000

ADU / Guest House cost in other California cities

Modesto
$100,000 – $240,000 | Stanislaus County
Pleasant Hill
$131,250 – $315,000 | Contra Costa County
Saratoga
$168,750 – $405,000 | Santa Clara County
Livermore
$131,250 – $315,000 | Alameda County
Danville
$150,000 – $360,000 | Contra Costa County
Corte Madera
$150,000 – $360,000 | Marin County
Hayward
$131,250 – $315,000 | Alameda County
Walnut Creek
$143,750 – $345,000 | Contra Costa County

Get a personalized estimate

Use our interactive cost estimator to adjust square footage and see detailed pricing for your specific project.

Open Cost Estimator →