Fremont, Alameda County

Room Addition Cost in Fremont, CA

Fremont remodeling costs are 15% abovethe California state average. Here's what a typical room addition costs in Fremont in 2026, based on a 300 sqf project.

Budget
$69,000
$230/sqf
Mid-Range
$120,750
$402/sqf
High-End
$189,750
$633/sqf

Cost breakdown

Foundation & Framing
30%$36,225
Roofing & Exterior
15%$18,113
Mechanical (HVAC, Electrical)
15%$18,113
Interior Finishes
20%$24,150
Windows & Doors
10%$12,075
Permits & Engineering
10%$12,075

Breakdown based on mid-range estimate of $120,750

Typical Timeline
3-6 months
Permits Required

Building permit, structural engineering, possibly zoning approval.

Remodeling in Fremont

Fremont offers Bay Area quality at slightly lower costs. Many 1960s-70s tract homes are being modernized. The city has been proactive about streamlining building permits.

A room addition adds square footage and value to your home. Costs depend on whether it's a simple bump-out, a second story, or a full wing addition with plumbing.

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Other projects in Fremont

Kitchen Remodel
$34,500 – $103,500
Bathroom Remodel
$17,250 – $55,200
ADU / Guest House
$143,750 – $345,000
Roof Replacement
$14,375 – $43,125
Exterior Paint
$5,750 – $20,125
Whole House Remodel
$310,500 – $1,035,000

Room Addition cost in other California cities

Walnut Creek
$69,000 – $189,750 | Contra Costa County
Camarillo
$60,000 – $165,000 | Ventura County
Campbell
$72,000 – $198,000 | Santa Clara County
Pacifica
$72,000 – $198,000 | San Mateo County
Burlingame
$78,000 – $214,500 | San Mateo County
Long Beach
$60,000 – $165,000 | Los Angeles County
Sunnyvale
$75,000 – $206,250 | Santa Clara County
Los Angeles
$63,000 – $173,250 | Los Angeles County

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