California Remodel Cost vs. Value › Counties
Caissonix report · 2026 pilot edition · 58 counties
California Remodel Cost vs. Value by County 2026
Home values vary several-fold across California, so a remodel that pays off in one county may not in the next. This table covers all 58 counties.
Local figures (3 counties: Los Angeles, San Francisco, Sonoma) come from our own analysis of that county's public sales or assessor records. Every other county shows a regional estimate: a lower-confidence figure borrowed from the most similar counties that do have local data, by region, price tier and age of the housing stock. Regional estimates are not that county's own data.
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.
Measured in local records
- Los Angeles County (43,190 single-family sales): one more full bathroom about $34,000 ($30,000–$38,000); 300 added sq ft about $79,000 against a likely cost of $144,900. Homes with a second unit or ADU: -2.1% (-5.7% to +1.6%) versus similar homes without one, not a measurable difference (based on 180 sales the roll records with a second unit; many newer ADUs may not be reflected yet).
- San Francisco County (2,362 single-family sales): one more full bathroom about $78,000 ($47,000–$110,000); 300 added sq ft about $193,000 against a likely cost of $156,600.
- Sonoma County (9,921 single-family sales): one more full bathroom about $51,000 ($38,000–$64,000); 300 added sq ft about $86,000 against a likely cost of $149,600. Homes with a second unit or ADU: -0.5% (-3.4% to +2.5%) versus similar homes without one, not a measurable difference (based on 451 sales the roll records with a second unit; many newer ADUs may not be reflected yet).
- San Francisco, building permits linked to sales (23,358 sale pairs): room addition +34% (+23% to +45%), about $471,000 (median +609 sq ft added); several projects at once (broader renovation) +15% (+7% to +22%), about $204,000. Medium confidence. No clear effect: kitchen remodel, bathroom remodel, roof replacement, window replacement, deck. All results.
- City of Los Angeles, building permits linked to sales (27,989 sale pairs): room addition +19% (+13% to +25%), about $204,000 (median +240 sq ft added); ADU +17% (+11% to +24%), about $185,000 (median 484 sq ft ADU). Medium confidence. No clear effect: kitchen remodel, bathroom remodel, roof replacement, seismic retrofit. All results.
Values are at each county's median just-sold single-family home. They measure what buyers paid for homes that already had the feature, which is not the same as the payoff from building it.
Bay Area
| County | Data | Typical home | Extra full bath: value | 300 sq ft addition: cost | Addition: value | 600 sq ft ADU: cost | ADU: value |
|---|---|---|---|---|---|---|---|
| Alameda | Regional estimate low confidence | $1.13M | $53k $25k to $81k · regional est. | $157k | $108k $73k to $145k · regional est. | $302k | Coming |
| Contra Costa | Regional estimate low confidence | $858k | $46k $24k to $67k · regional est. | $156k | $84k $57k to $111k · regional est. | $301k | Coming |
| Marin | Regional estimate low confidence | $1.62M | $75k $35k to $116k · regional est. | $156k | $159k $108k to $211k · regional est. | $301k | Coming |
| Napa | Regional estimate low confidence | $859k | $44k $23k to $66k · regional est. | $148k | $83k $56k to $111k · regional est. | $284k | Coming |
| San Francisco | Local | $1.32M | $78k $47k to $110k · local | $157k | $193k $176k to $210k · local | $303k | Coming |
| San Mateo | Regional estimate low confidence | $1.61M | $74k $34k to $114k · regional est. | $157k | $157k $107k to $209k · regional est. | $303k | Coming |
| Santa Clara | Regional estimate low confidence | $1.65M | $84k $43k to $126k · regional est. | $158k | $164k $113k to $217k · regional est. | $305k | Coming |
| Solano | Regional estimate low confidence | $621k | $34k $19k to $50k · regional est. | $144k | $61k $42k to $81k · regional est. | $278k | Coming |
| Sonoma | Local | $819k | $51k $38k to $64k · local | $150k | $86k $82k to $90k · local | $286k | No clear effect -3% to +2% · local |
Central Coast
| County | Data | Typical home | Extra full bath: value | 300 sq ft addition: cost | Addition: value | 600 sq ft ADU: cost | ADU: value |
|---|---|---|---|---|---|---|---|
| Monterey | Regional estimate low confidence | $862k | $43k $22k to $65k · regional est. | $140k | $82k $55k to $110k · regional est. | $271k | Coming |
| San Benito | Regional estimate low confidence | $802k | $43k $23k to $63k · regional est. | $157k | $78k $53k to $104k · regional est. | $303k | Coming |
| San Luis Obispo | Regional estimate low confidence | $878k | $46k $24k to $68k · regional est. | $143k | $85k $57k to $113k · regional est. | $274k | Coming |
| Santa Barbara | Regional estimate low confidence | $858k | $44k $23k to $66k · regional est. | $138k | $82k $56k to $110k · regional est. | $267k | Coming |
| Santa Cruz | Regional estimate low confidence | $1.08M | $52k $26k to $80k · regional est. | $143k | $103k $70k to $138k · regional est. | $276k | Coming |
Southern California
| County | Data | Typical home | Extra full bath: value | 300 sq ft addition: cost | Addition: value | 600 sq ft ADU: cost | ADU: value |
|---|---|---|---|---|---|---|---|
| Imperial | Regional estimate low confidence | $343k | $18k $9k to $26k · regional est. | $136k | $33k $22k to $44k · regional est. | $263k | Coming |
| Los Angeles | Local | $871k | $34k $30k to $38k · local | $145k | $79k $76k to $81k · local | $280k | No clear effect -6% to +2% · local |
| Orange | Regional estimate low confidence | $1.10M | $54k $27k to $82k · regional est. | $145k | $105k $71k to $140k · regional est. | $278k | Coming |
| Riverside | Regional estimate low confidence | $609k | $31k $16k to $47k · regional est. | $138k | $58k $39k to $78k · regional est. | $267k | Coming |
| San Bernardino | Regional estimate low confidence | $547k | $28k $14k to $42k · regional est. | $137k | $52k $35k to $70k · regional est. | $266k | Coming |
| San Diego | Regional estimate low confidence | $928k | $46k $23k to $70k · regional est. | $143k | $88k $59k to $117k · regional est. | $276k | Coming |
| Ventura | Regional estimate low confidence | $860k | $43k $22k to $65k · regional est. | $139k | $81k $55k to $109k · regional est. | $267k | Coming |
San Joaquin Valley
| County | Data | Typical home | Extra full bath: value | 300 sq ft addition: cost | Addition: value | 600 sq ft ADU: cost | ADU: value |
|---|---|---|---|---|---|---|---|
| Fresno | Regional estimate low confidence | $411k | $22k $12k to $32k · regional est. | $136k | $40k $27k to $53k · regional est. | $263k | Coming |
| Kern | Regional estimate low confidence | $370k | $20k $11k to $29k · regional est. | $136k | $36k $24k to $48k · regional est. | $263k | Coming |
| Kings | Regional estimate low confidence | $342k | $18k $10k to $27k · regional est. | $142k | $33k $23k to $44k · regional est. | $270k | Coming |
| Madera | Regional estimate low confidence | $455k | $24k $13k to $36k · regional est. | $136k | $44k $30k to $59k · regional est. | $262k | Coming |
| Merced | Regional estimate low confidence | $424k | $23k $12k to $33k · regional est. | $134k | $41k $28k to $55k · regional est. | $261k | Coming |
| San Joaquin | Regional estimate low confidence | $544k | $29k $15k to $43k · regional est. | $136k | $53k $36k to $70k · regional est. | $264k | Coming |
| Stanislaus | Regional estimate low confidence | $480k | $26k $14k to $38k · regional est. | $140k | $47k $32k to $62k · regional est. | $269k | Coming |
| Tulare | Regional estimate low confidence | $369k | $20k $11k to $29k · regional est. | $130k | $36k $24k to $48k · regional est. | $254k | Coming |
Sacramento Valley and the North State
| County | Data | Typical home | Extra full bath: value | 300 sq ft addition: cost | Addition: value | 600 sq ft ADU: cost | ADU: value |
|---|---|---|---|---|---|---|---|
| Butte | Regional estimate low confidence | $418k | $22k $12k to $33k · regional est. | $135k | $41k $28k to $54k · regional est. | $261k | Coming |
| Colusa | Regional estimate low confidence | $393k | $19k $10k to $29k · regional est. | $139k | $37k $25k to $50k · regional est. | $267k | Coming |
| Glenn | Regional estimate low confidence | $352k | $18k $9k to $27k · regional est. | $137k | $34k $23k to $45k · regional est. | $265k | Coming |
| Sacramento | Regional estimate low confidence | $543k | $29k $15k to $43k · regional est. | $141k | $53k $36k to $70k · regional est. | $271k | Coming |
| Shasta | Regional estimate low confidence | $394k | $21k $11k to $31k · regional est. | $136k | $38k $26k to $51k · regional est. | $263k | Coming |
| Sutter | Regional estimate low confidence | $454k | $24k $13k to $36k · regional est. | $138k | $44k $30k to $59k · regional est. | $264k | Coming |
| Tehama | Regional estimate low confidence | $340k | $18k $10k to $27k · regional est. | $139k | $33k $23k to $44k · regional est. | $266k | Coming |
| Yolo | Regional estimate low confidence | $613k | $33k $17k to $48k · regional est. | $140k | $60k $41k to $79k · regional est. | $270k | Coming |
| Yuba | Regional estimate low confidence | $419k | $22k $12k to $33k · regional est. | $139k | $41k $28k to $54k · regional est. | $267k | Coming |
Sierra Nevada and Gold Country
| County | Data | Typical home | Extra full bath: value | 300 sq ft addition: cost | Addition: value | 600 sq ft ADU: cost | ADU: value |
|---|---|---|---|---|---|---|---|
| Alpine | Regional estimate low confidence | $590k | $31k $17k to $46k · regional est. | $150k | $57k $39k to $76k · regional est. | $291k | Coming |
| Amador | Regional estimate low confidence | $450k | $24k $13k to $35k · regional est. | $139k | $44k $30k to $58k · regional est. | $270k | Coming |
| Calaveras | Regional estimate low confidence | $457k | $24k $13k to $36k · regional est. | $140k | $44k $30k to $59k · regional est. | $270k | Coming |
| El Dorado | Regional estimate low confidence | $664k | $35k $19k to $52k · regional est. | $141k | $65k $44k to $86k · regional est. | $270k | Coming |
| Inyo | Regional estimate low confidence | $349k | $18k $9k to $27k · regional est. | $146k | $34k $23k to $45k · regional est. | $282k | Coming |
| Mariposa | Regional estimate low confidence | $388k | $21k $11k to $31k · regional est. | $146k | $38k $26k to $50k · regional est. | $281k | Coming |
| Mono | Regional estimate low confidence | $639k | $34k $18k to $50k · regional est. | $150k | $62k $42k to $83k · regional est. | $290k | Coming |
| Nevada | Regional estimate low confidence | $570k | $30k $16k to $45k · regional est. | $138k | $55k $38k to $74k · regional est. | $268k | Coming |
| Placer | Regional estimate low confidence | $694k | $37k $20k to $55k · regional est. | $141k | $67k $46k to $90k · regional est. | $268k | Coming |
| Plumas | Regional estimate low confidence | $360k | $19k $10k to $28k · regional est. | $148k | $35k $24k to $47k · regional est. | $286k | Coming |
| Sierra | Regional estimate low confidence | $332k | $16k $8k to $25k · regional est. | $148k | $31k $21k to $42k · regional est. | $286k | Coming |
| Tuolumne | Regional estimate low confidence | $433k | $23k $12k to $34k · regional est. | $139k | $42k $29k to $56k · regional est. | $269k | Coming |
North Coast and the far north
| County | Data | Typical home | Extra full bath: value | 300 sq ft addition: cost | Addition: value | 600 sq ft ADU: cost | ADU: value |
|---|---|---|---|---|---|---|---|
| Del Norte | Regional estimate low confidence | $342k | $18k $10k to $27k · regional est. | $143k | $33k $23k to $44k · regional est. | $275k | Coming |
| Humboldt | Regional estimate low confidence | $459k | $22k $11k to $34k · regional est. | $142k | $43k $29k to $58k · regional est. | $276k | Coming |
| Lake | Regional estimate low confidence | $325k | $17k $9k to $26k · regional est. | $142k | $32k $22k to $42k · regional est. | $278k | Coming |
| Lassen | Regional estimate low confidence | $265k | $13k $7k to $20k · regional est. | $145k | $25k $17k to $34k · regional est. | $279k | Coming |
| Mendocino | Regional estimate low confidence | $488k | $25k $13k to $37k · regional est. | $142k | $47k $32k to $62k · regional est. | $276k | Coming |
| Modoc | Regional estimate low confidence | $225k | $11k $6k to $17k · regional est. | $144k | $21k $14k to $29k · regional est. | $278k | Coming |
| Siskiyou | Regional estimate low confidence | $310k | $15k $8k to $23k · regional est. | $138k | $29k $20k to $39k · regional est. | $265k | Coming |
| Trinity | Regional estimate low confidence | $326k | $17k $9k to $25k · regional est. | $145k | $31k $21k to $42k · regional est. | $279k | Coming |
How to read this table
- County links to that county's remodel cost page in our estimator.
- Typical home value: Census ACS median value of owner-occupied homes (2025 1-year estimate where the Census publishes one, otherwise the 2020–2024 5-year estimate).
- Cost: the likely cost from the Caissonix estimator at one example ZIP in the county, for the same fixed scope everywhere (see each project page).
- Value: likely figure, then the 95% range. Local means measured in that county's own records. Regional estimate (low) means estimated from similar counties with local data; the range is wider because it includes how much counties differ from one another. Treat it as a rough guide, not as that county's data.
- Coming: no local measurement and not enough local results elsewhere to borrow from. ADU values are not borrowed across counties because they depend heavily on local rules and rents.
- The room addition value assumes a typical 1,700 sq ft home where no local home size is measured.
County data inventory
We searched every county for open assessor, sales and building permit data and checked each license. 3 counties have open data we can use for value today, 3 publish home details without sale prices, 13 have copies or partial layers we cannot use yet, and 39 have nothing open we could find (many assessors sell their data or provide it on request).
Show all 58 counties
| County | Status | Source found | License | Building permits |
|---|---|---|---|---|
| Alameda County | Nothing open found | — | — | No open countywide permit dataset found |
| Alpine County | Found, not usable yet | Parcels - CA - Alpine County (federal contractor copy) | Not stated (unverified) | No open countywide permit dataset found |
| Amador County | Nothing open found | — | — | No open countywide permit dataset found |
| Butte County | Found, not usable yet | Butte County Parcels 2025 (personal ArcGIS copy) | Not stated (unverified) | No open countywide permit dataset found |
| Calaveras County | Nothing open found | — | — | No open countywide permit dataset found |
| Colusa County | Nothing open found | — | — | No open countywide permit dataset found |
| Contra Costa County | Nothing open found | — | — | No open countywide permit dataset found |
| Del Norte County | Nothing open found | — | — | No open countywide permit dataset found |
| El Dorado County | Found, not usable yet | El Dorado Parcels Heavenly Valley (partial area) | Not stated (unverified) | No open countywide permit dataset found |
| Fresno County | Found, not usable yet | Fresno_Parcels (third-party copy) | Not stated (unverified) | No open countywide permit dataset found |
| Glenn County | Nothing open found | — | — | No open countywide permit dataset found |
| Humboldt County | Nothing open found | — | — | No open countywide permit dataset found |
| Imperial County | Nothing open found | — | — | No open countywide permit dataset found |
| Inyo County | Nothing open found | — | — | No open countywide permit dataset found |
| Kern County | Nothing open found | — | — | No open countywide permit dataset found |
| Kings County | Found, not usable yet | Kings County Regrid Parcels (City of Hanford) | Commercial parcel vendor copy; no license for our use (excluded) | No open countywide permit dataset found |
| Lake County | Nothing open found | — | — | No open countywide permit dataset found |
| Lassen County | Nothing open found | — | — | No open countywide permit dataset found |
| Los Angeles County | Used: local values | County of Los Angeles, Assessor Parcel Data (Rolls 2006-present) | County of Los Angeles eGIS terms: commercial use allowed with attribution, no endorsement | Partial: LA County and City of LA publish permit data on their portals |
| Madera County | Nothing open found | — | — | No open countywide permit dataset found |
| Marin County | Nothing open found | — | — | No open countywide permit dataset found |
| Mariposa County | Nothing open found | — | — | No open countywide permit dataset found |
| Mendocino County | Nothing open found | — | — | No open countywide permit dataset found |
| Merced County | Nothing open found | — | — | No open countywide permit dataset found |
| Modoc County | Nothing open found | — | — | No open countywide permit dataset found |
| Mono County | Nothing open found | — | — | No open countywide permit dataset found |
| Monterey County | Found, not usable yet | Monterey County Parcels (Monterey Peninsula Regional Park District copy) | Not stated; not published by the county (unverified) | No open countywide permit dataset found |
| Napa County | Found, not usable yet | Parcels County (published by City of Napa from Napa County Assessor data) | Not stated (unverified) | No open countywide permit dataset found |
| Nevada County | Home details, no sale prices | County of Nevada, Parcel Information (Open Data Layers) | CC BY 4.0 | No open countywide permit dataset found |
| Orange County | Nothing open found | — | — | No open countywide permit dataset found |
| Placer County | Nothing open found | — | — | Dashboard only (not a downloadable dataset) |
| Plumas County | Nothing open found | — | — | No open countywide permit dataset found |
| Riverside County | Nothing open found | — | — | No open countywide permit dataset found |
| Sacramento County | Nothing open found | — | — | City of West Sacramento only |
| San Benito County | Nothing open found | — | — | No open countywide permit dataset found |
| San Bernardino County | Nothing open found | — | — | No open countywide permit dataset found |
| San Diego County | Nothing open found | — | — | Third-party map only |
| San Francisco County | Used: local values | DataSF Assessor Historical Secured Property Tax Rolls (wv5m-vpq2) | PDDL 1.0 (public domain dedication) | Open: DataSF building permits |
| San Joaquin County | Home details, no sale prices | San Joaquin County Public Works, Parcels | Not stated on the item (unverified) | No open countywide permit dataset found |
| San Luis Obispo County | Nothing open found | — | — | No open countywide permit dataset found |
| San Mateo County | Nothing open found | — | — | No open countywide permit dataset found |
| Santa Barbara County | Found, not usable yet | Santa Barbara County Clerk-Recorder-Assessor, Assessor Parcels Public | Not stated (liability disclaimer only) (unverified) | No open countywide permit dataset found |
| Santa Clara County | Nothing open found | — | — | No open countywide permit dataset found |
| Santa Cruz County | Nothing open found | — | — | No open countywide permit dataset found |
| Shasta County | Nothing open found | — | — | No open countywide permit dataset found |
| Sierra County | Nothing open found | — | — | No open countywide permit dataset found |
| Siskiyou County | Found, not usable yet | ca_siskiyou_parcel_gdb (commercial parcel vendor schema) | Appears to be a commercial parcel vendor copy; no license for our use (excluded) | No open countywide permit dataset found |
| Solano County | Home details, no sale prices | Solano County DoIT GIS, Parcels Public Aumentum | Not stated (accuracy disclaimer only) (unverified) | No open countywide permit dataset found |
| Sonoma County | Used: local values | County of Sonoma, Parcels Public (CRAPublic) | CC BY-SA 3.0 US (attribution, share-alike on derived data) | Open: Permit Sonoma building permits (data.sonomacounty.ca.gov 88ms-k5e7) |
| Stanislaus County | Nothing open found | — | — | No open countywide permit dataset found |
| Sutter County | Nothing open found | — | — | No open countywide permit dataset found |
| Tehama County | Found, not usable yet | Tehama County Transportation copy | Not stated (unverified) | No open countywide permit dataset found |
| Trinity County | Nothing open found | — | — | No open countywide permit dataset found |
| Tulare County | Nothing open found | — | — | No open countywide permit dataset found |
| Tuolumne County | Found, not usable yet | Tuolumne County Owned Parcels | Not stated (unverified) | No open countywide permit dataset found |
| Ventura County | Found, not usable yet | Ventura County Parcels (personal ArcGIS copy) | Not stated; not published by the county (unverified) | No open countywide permit dataset found |
| Yolo County | Found, not usable yet | Yolo Parcels, Williamson Act subset | Not stated (unverified) | No open countywide permit dataset found |
| Yuba County | Nothing open found | — | — | No open countywide permit dataset found |
Download the county data
Download the county table (CSV)
All 58 counties with costs, values, ranges, data status and sources. Licensed CC BY-SA 4.0 because it includes figures derived from County of Sonoma data licensed under CC BY-SA 3.0 US: credit "Caissonix California Remodel Cost vs. Value 2026", link to this page, and share adaptations under the same license.
Local figures use: San Francisco Assessor-Recorder roll data (DataSF, public domain dedication); Los Angeles County Assessor parcel data (Courtesy of the County of Los Angeles); County of Sonoma parcel data (licensed under CC BY-SA 3.0 US). Regional estimates are derived from those local results and Census ACS data.
Caissonix California Remodel Cost vs. Value by County, 2026 pilot edition, published 2026-10-31. 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. Neither Los Angeles County nor the County of Sonoma endorses Caissonix.