🏡 Home Addition Cost in California
How much does a home addition cost in California? See local labor rates, material costs, and get a free estimate.
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California Average Cost (2026)
$57,000 – $126,000
Average: $84,000 for a 300 sq ft project
California is in the West region. Labor costs in this region tend to be above the national average.
Cost Breakdown
Economy
$57,000
Standard
$84,000
Premium
$126,000
Est. labor: $46,200
Est. materials: $37,800
Recommended Materials & Tools
Popular items for this project — links may earn a commission.
DuPont Tyvek HomeWrap — 3' x 100'
Weather-resistant barrier, blocks wind and moisture, vapor permeable
$95Amazon
Owens Corning R-19 Kraft Faced Fiberglass Insulation — 10 Bags
16" x 96" batts, fits 2x6 exterior walls, 853 sq ft coverage
$175Amazon
Johns Manville R-19 Kraft Faced Fiberglass Batts — 10 Bags
15" x 105" batts, fits 2x6 exterior walls, 1094 sq ft coverage
$195Amazon
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How big is your home addition?
A bedroom addition is typically 150–300 sq ft.
sq ft
100 sq ft1000 sq ft
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