California Remodel Cost vs. Value › Projects
Caissonix report · 2026 · 13 California cities
Does a Garage Conversion Add Value in California?
A peer-reviewed Los Angeles study (Brueckner and Thomaz, 2024) found an ADU raised the value of just-sold homes by close to 9%, and 7%–8% across all homes. On the City of Los Angeles median owner-occupied home value of $951,800 (Census ACS 2025), 7%–9% is $66,600–$85,700, against our likely cost of $139,800 for this project in Los Angeles.
The study covered every kind of ADU, many of them smaller or older than a new unit, and a sale price does not count rent collected while you own the home. We show a dollar figure for Los Angeles only, because that is where the study measured. Our likely cost runs from $130,200 in Riverside to $153,900 in San Jose for the same job.
Not an appraisal, a broker price opinion or a prediction of a sale price. Costs are budget estimates, not a bid, appraisal, or insurance claim valuation. Pilot.
The project we priced
Garage conversion ADU (400 sq ft). Convert a 400 sq ft garage into an ADU with one bathroom and a kitchenette.
Same scope in every city, mid-range finishes. Your own home, size and finish choices will differ.
Garage conversion ADU (400 sq ft): cost by California city
| City | Likely cost | Range | Share of median home value |
|---|---|---|---|
| San Francisco (Bay Area) | $152,400 | $126,100–$182,600 | 12% |
| Oakland (Bay Area) | $151,000 | $125,300–$181,400 | 17% |
| San Jose (Bay Area) | $153,900 | $128,400–$184,800 | 11% |
| Los Angeles (Los Angeles and Orange County) | $139,800 | $116,800–$166,400 | 15% |
| Long Beach (Los Angeles and Orange County) | $139,400 | $115,900–$166,600 | 16% |
| Irvine (Los Angeles and Orange County) | $137,700 | $114,400–$165,200 | 8% |
| San Diego (San Diego) | $137,400 | $115,100–$162,800 | 14% |
| Sacramento (Sacramento) | $134,900 | $112,600–$161,600 | 26% |
| Riverside (Inland Empire) | $130,200 | $108,400–$156,800 | 20% |
| San Bernardino (Inland Empire) | $131,600 | $109,700–$157,200 | 29% |
| Fresno (Central Valley) | $132,000 | $110,300–$158,300 | 33% |
| Bakersfield (Central Valley) | $132,000 | $109,700–$156,500 | 32% |
| Stockton (Central Valley) | $131,400 | $110,700–$156,800 | 29% |
Likely is the median of 4,000 simulated outcomes from our estimator; the range is the 10th to 90th percentile. Share of median home value compares the likely cost with the city's median owner-occupied home value (U.S. Census Bureau, ACS 2025 1-year, table B25077).
Resale value: what we can verify
| City | Value added | Range | Likely cost | Value ÷ cost | Confidence |
|---|---|---|---|---|---|
| Los Angeles | $76,100 | $66,600–$85,700 | $139,800 | 54% | Low |
Source: Brueckner and Thomaz, "ADUs in Los Angeles: Where are they located and by how much do they raise property value?", Real Estate Economics (2024). https://doi.org/10.1111/1540-6229.12471
Other cities (San Francisco, Oakland, San Jose, Long Beach, Irvine, San Diego, Sacramento, Riverside, San Bernardino, Fresno, Bakersfield, Stockton): no value figure yet. We do not stretch one city's result to another.
Questions
How much does a garage conversion adu cost in California?
For the fixed scope on this page (Convert a 400 sq ft garage into an ADU with one bathroom and a kitchenette), our likely cost runs from $130,200 in Riverside to $153,900 in San Jose. Your size, finishes and ZIP change it; the free estimator recalculates it line by line.
Does a Garage Conversion Add Value in California?
A peer-reviewed Los Angeles study (Brueckner and Thomaz, 2024) found an ADU raised the value of just-sold homes by close to 9%, and 7%–8% across all homes. On the City of Los Angeles median owner-occupied home value of $951,800 (Census ACS 2025), 7%–9% is $66,600–$85,700, against our likely cost of $139,800 for this project in Los Angeles.
Is this an appraisal?
No. It is an informational report: budget cost estimates plus the resale value evidence we can verify from public records and published studies. It is not an appraisal, a broker price opinion or a prediction of what your home will sell for. For a valuation, ask a licensed appraiser or a local real estate professional.
Caissonix California Remodel Cost vs. Value, 2026 pilot edition. Cost figures computed 2026-10-31 from engine 0.10.0, price book 2026-10-31.1. Not an appraisal, a broker price opinion or a prediction of a sale price. Costs are budget estimates, not a bid, appraisal, or insurance claim valuation. Get licensed contractor bids before you decide.