Walnut Creek 94597 · APN 148-300-012-9 · Unincorporated Contra Costa
Since — within ½ mile: 2 homes completed, 2 permitted, 150 proposed or in review.
6 projects with a record in this window, grouped by us from permits and State housing reports. Units are as proposed on each project's latest record and counted at its current stage.
No permit activity recorded within ½ mile.
$1,019,000
Benchmark range: $866,000 – $1,172,000
Public-records benchmark estimate combining Zillow Home Value Index (Data provided by Zillow), Census ACS 5-year estimates, parcel land-use/lot characteristics, and issued building permits. Not an official appraisal.
We don't have building permits for Unincorporated Contra Costa, so we can't show what has been permitted nearby.
Permit counts, by the date issued (or applied, if not yet issued). Lot splits are planning cases, which we don't have.
We read public zoning and hazard maps against state law (ADUs: Gov. Code 66314; SB 9: Gov. Code 65852.21 and 66411.7). Local rules, title, tenancy history and site conditions can change the answer. Check with Unincorporated Contra Costa's planning department before relying on it.
Sources: Contra Costa County Department of Conservation and Development, Zoning (unincorporated Contra Costa) (retrieved Oct 26, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the State Responsibility Area (effective 2024-04-01) (retrieved Oct 26, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the Local Responsibility Area (map dated 2025-03-24) (retrieved Oct 26, 2026) · FEMA, National Flood Hazard Layer — flood hazard zones (retrieved Oct 26, 2026) · FEMA, National Flood Hazard Layer — FIRM panels (retrieved Oct 26, 2026) · California Geological Survey, Alquist-Priolo Earthquake Fault Zones (retrieved Oct 26, 2026) · Zoning classes: our classification of M-17 as multifamily residential, checked against the zone description on Oct 24, 2026
Chronological history of building permit applications and issuances, snapshot-dated status changes, State housing entitlements, surrounding development within ½ mile, and area home-value trends.
In "Entitled" for 23 mo (since Dec 6, 2024), with no new permit record in 23 mo. · 1 unit
Permit issued and active for 9.6 yr (first record Apr 17, 2017), with no completion or new permit record in 9.6 yr. · 1 unit
Permit issued and active for 9.6 yr (first record Apr 17, 2017), with no completion or new permit record in 9.6 yr. · 1 unit
Permit issued and active for 9.6 yr (first record Apr 17, 2017), with no completion or new permit record in 9.6 yr. · 1 unit
Permit issued and active for 9.6 yr (first record Apr 17, 2017), with no completion or new permit record in 9.6 yr. · 1 unit
Permit issued and active for 9.6 yr (first record Apr 17, 2017), with no completion or new permit record in 9.6 yr. · 1 unit
Latest published Zillow Home Value Index (ZHVI) update
Changed from $959,842 in September 2025 to $972,248 in September 2026.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94597 (not a parcel appraisal)
Annual ZIP 94597 home-value index checkpoint
Changed from $982,209 in September 2024 to $959,842 in September 2025.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94597 (not a parcel appraisal)
Building permit reported to State HCD for 1 housing unit (BIMP25-003158; CDSU24-00073)
Reported in 2025 Housing Element Annual Progress Report
ADU · Renter
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: parcel
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
149 units
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
Planning entitlement approved for 1 housing unit (BIMP25-003158; CDSU24-00073)
Reported in 2025 Housing Element Annual Progress Report
ADU · Renter
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: parcel
Planning entitlement approved for 1 housing unit (CDSU24-00073)
Reported in 2024 Housing Element Annual Progress Report
ADU · Renter
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: parcel
1 unit
Records span May 5, 2022 to Nov 6, 2024 (0 permits).
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
Annual ZIP 94597 home-value index checkpoint
Changed from $966,608 in September 2023 to $982,209 in September 2024.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94597 (not a parcel appraisal)
Annual ZIP 94597 home-value index checkpoint
Changed from $993,551 in September 2022 to $966,608 in September 2023.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94597 (not a parcel appraisal)
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
Cross-referenced intelligence from our historical development graph—connecting parcels, permits, entity-resolved builders, empirical review-time distributions, and neighborhood renovation trends.
Explore full Unincorporated Contra Costa development graph →Active in "Entitled" for 23 mo (first record Dec 6, 2024) with no new permit activity recorded in 23 mo.
Active in "Issued" for 23 mo (first record Dec 6, 2024) with no new permit activity recorded in 23 mo.
Active in "Entitled" for 22 mo (first record Jan 16, 2025) with no new permit activity recorded in 22 mo. High-impact scale (149 housing units across 0 permits).
Active in "Entitled" for 8.4 yr (first record Jun 20, 2018) with no new permit activity recorded in 8.4 yr. High-impact scale (42 housing units, 42 deed-restricted affordable across 0 permits).
Active in "Issued" for 22 mo (first record Dec 26, 2024) with no new permit activity recorded in 22 mo.
Active in "Issued" for 9.6 yr (first record Apr 17, 2017) with no new permit activity recorded in 9.6 yr.
HUD Small Area Fair Market Rent · ZIP 94597
HUD FY 2026 · 40th-percentile gross rentCensus ACS 5-year median gross rent (all bedroom counts combined):
Area home-value benchmarks (not an appraisal)
ZIP & neighborhood mediansUnder California Proposition 13, the seller's historical assessed value does not carry over to a buyer. On sale, the parcel is reassessed at the purchase price: 1.00% base rate ($10,200/yr) + local voter-approved bond debt ($1,836/yr) + fixed direct levies/Mello-Roos ($450/yr).
Insurance & hazard context:
−$46,172/yr
Cash needed: $224,400
NOI: $15,720/yr
P&I: $5,158/mo
For $0/mo net cash flow
At $3,250/mo rent
| Scenario | Assumptions | Year 1 Rent | Year 1 Cash Flow | Cash-on-Cash | Break-Even Rent | Year 5 Cash Flow |
|---|---|---|---|---|---|---|
| Conservative | −8% starting rent, +3% vacancy, +3% combined maintenance/CapEx, 1.5%/yr rent growth | $2,990/mo | −$4,221/mo | -22.6% | $8,882/mo | −$4,190/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $3,250/mo | −$3,848/mo | -20.6% | $8,221/mo | −$3,632/mo |
| Optimistic (cap-limited) | +6% starting rent, 3% vacancy, 4.5%/yr rent growth (capped by AB 1482 ceiling of 8.6%/yr) | $3,445/mo | −$3,633/mo | -19.4% | $8,030/mo | −$3,208/mo |
Rental regulatory context (informational only — not legal advice):
California AB 1482 (Tenant Protection Act, Civ. Code § 1947.12) caps annual rent increases at 5% + local CPI (max 10%) on covered properties.
No building permits are recorded for this parcel since 2016.
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) · Geography: parcel (APN) · Retrieved Oct 26, 2026 · Richmond's permits come from its eTRAKiT system, retired in 2025. Statuses are as of April 2025, and later permits are not published.
| Report year | Project / record | Type | Entitled | Permitted | Completed | Deed-restricted |
|---|---|---|---|---|---|---|
| 2025 | —(BIMP25-003158; CDSU24-00073) | ADU · Renter | 1 (Dec 6, 2024) | 1 (Aug 19, 2025) | — | — |
| 2024 | —(CDSU24-00073) | ADU · Renter | 1 (Dec 6, 2024) | — | — | — |
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: project (parcel) · Retrieved Oct 26, 2026 · From Unincorporated Contra Costa's Housing Element Annual Progress Reports. A project can appear in several report years as it moves from entitlement to permit to completion.
Source: Contra Costa County Department of Conservation and Development, Zoning (unincorporated Contra Costa) · Geography: zoning district polygon at parcel point · Retrieved Oct 26, 2026
0.25 acres
Assessor's classification for assessment purposes. This is not zoning.
203 MAYHEW WAY
Source: Contra Costa County Assessor / Department of Information Technology, Assessment Parcels · Geography: parcel · Retrieved Oct 26, 2026
County map with assessor parcel maps and zoning. Search parcel 148-300-012.
Search by parcel number 148-300-012 (Contra Costa County Treasurer-Tax Collector). Assessed value is not market value.
The official flood hazard map for this location. Our reading of it is under What could be built here.
This site does not show owner names.