San Carlos, San Mateo County

ADU / Guest House Cost in San Carlos, CA

San Carlos remodeling costs are 25% abovethe California state average. Here's what a typical adu / guest house costs in San Carlos in 2026, based on a 500 sqf project.

Budget
$156,250
$313/sqf
Mid-Range
$250,000
$500/sqf
High-End
$375,000
$750/sqf

Cost breakdown

Foundation & Framing
25%$62,500
Mechanical (HVAC, Plumbing, Electrical)
20%$50,000
Interior Finishes
20%$50,000
Exterior & Roofing
15%$37,500
Kitchen & Bath Fixtures
10%$25,000
Permits, Plans & Engineering
10%$25,000

Breakdown based on mid-range estimate of $250,000

Typical Timeline
4-8 months
Permits Required

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

Remodeling in San Carlos

Family-friendly Peninsula city with active renovation market. Many 1940s-60s homes being expanded and modernized. The city has reasonable permit turnaround times for the area.

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.

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Other projects in San Carlos

Kitchen Remodel
$37,500 – $112,500
Bathroom Remodel
$18,750 – $60,000
Room Addition
$75,000 – $206,250
Roof Replacement
$15,625 – $46,875
Exterior Paint
$6,250 – $21,875
Whole House Remodel
$337,500 – $1,125,000

ADU / Guest House cost in other California cities

Redondo Beach
$137,500 – $330,000 | Los Angeles County
Elk Grove
$112,500 – $270,000 | Sacramento County
Sacramento
$112,500 – $270,000 | Sacramento County
Carlsbad
$137,500 – $330,000 | San Diego County
Burbank
$125,000 – $300,000 | Los Angeles County
Mission Viejo
$131,250 – $315,000 | Orange County
San Marcos
$118,750 – $285,000 | San Diego County
Lake Forest
$131,250 – $315,000 | Orange County

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