El Sobrante 94803 · APN 435-100-033-8 · Unincorporated Contra Costa
17 permits within ½ mile since November 2024
The map shows new construction, ADUs, demolitions, additions, and renovations. Routine systems work (roofs, HVAC, water heaters) is counted but not mapped. Unit counts are as stated on permits.
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) · Geography: permits located by parcel, ½ mile radius · Retrieved Nov 9, 2026
$773,000
Benchmark range: $657,000 – $889,000
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 Nov 9, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the State Responsibility Area (effective 2024-04-01) (retrieved Nov 9, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the Local Responsibility Area (map dated 2025-03-24) (retrieved Nov 9, 2026) · FEMA, National Flood Hazard Layer — flood hazard zones (retrieved Nov 9, 2026) · FEMA, National Flood Hazard Layer — FIRM panels (retrieved Nov 9, 2026) · California Geological Survey, Alquist-Priolo Earthquake Fault Zones (retrieved Nov 9, 2026) · Zoning classes: our classification of R-6 as single-family 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 6.2 yr (since Aug 11, 2020), with no new permit record in 6.2 yr. · 1 unit
Permit issued and active for 5.8 yr (first record Jan 27, 2021), with no completion or new permit record in 5.8 yr. · 1 unit
In "Entitled" for 8.1 yr (since Oct 19, 2018), with no new permit record in 8.1 yr. · 1 unit
Permit issued and active for 5.4 yr (first record Jun 9, 2021), with no completion or new permit record in 5.4 yr. · 1 unit
In "Entitled" for 5.3 yr (since Jul 26, 2021), with no new permit record in 5.3 yr. · 1 unit
In "Entitled" for 4.9 yr (since Dec 14, 2021), with no new permit record in 4.9 yr. · 1 unit
Latest published Zillow Home Value Index (ZHVI) update
Changed from $727,674 in September 2025 to $726,110 in September 2026.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94803 (not a parcel appraisal)
Annual ZIP 94803 home-value index checkpoint
Changed from $790,997 in September 2024 to $727,674 in September 2025.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94803 (not a parcel appraisal)
Annual ZIP 94803 home-value index checkpoint
Changed from $775,801 in September 2023 to $790,997 in September 2024.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94803 (not a parcel appraisal)
1 unit
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
Annual ZIP 94803 home-value index checkpoint
Changed from $817,971 in September 2022 to $775,801 in September 2023.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94803 (not a parcel appraisal)
1 unit
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
1 unit
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
Annual ZIP 94803 home-value index checkpoint
Changed from $782,031 in September 2021 to $817,971 in September 2022.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94803 (not a parcel appraisal)
1 unit
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 94803 home-value index checkpoint
Changed from $643,417 in September 2020 to $782,031 in September 2021.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94803 (not a parcel appraisal)
1 unit
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
1 unit
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)
Building permit reported to State HCD for 1 housing unit (BIR20-008443)
Reported in 2023 Housing Element Annual Progress Report
ADU · Renter
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: parcel
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 "Issued" for 5.8 yr (first record Jan 27, 2021) with no new permit activity recorded in 5.8 yr.
Active in "Entitled" for 6.2 yr (first record Aug 11, 2020) with no new permit activity recorded in 6.2 yr.
Active in "Entitled" for 8.1 yr (first record Oct 19, 2018) with no new permit activity recorded in 8.1 yr.
Active in "Entitled" for 5.3 yr (first record Jul 26, 2021) with no new permit activity recorded in 5.3 yr.
Active in "Entitled" for 2.3 yr (first record Aug 5, 2024) with no new permit activity recorded in 2.3 yr.
Active in "Entitled" for 4.9 yr (first record Dec 14, 2021) with no new permit activity recorded in 4.9 yr.
HUD Small Area Fair Market Rent · ZIP 94803
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 ($7,750/yr) + local voter-approved bond debt ($1,395/yr) + fixed direct levies/Mello-Roos ($450/yr).
Mapped hazard zone insurance context on this parcel:
−$34,379/yr
Cash needed: $170,500
NOI: $12,647/yr
P&I: $3,919/mo
For $0/mo net cash flow
At $2,750/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 | $2,530/mo | −$3,181/mo | -22.4% | $6,970/mo | −$3,161/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $2,750/mo | −$2,865/mo | -20.2% | $6,451/mo | −$2,689/mo |
| Optimistic (cap-limited) | +6% starting rent, 3% vacancy, 4.5%/yr rent growth (capped by AB 1482 ceiling of 8.6%/yr) | $2,915/mo | −$2,684/mo | -18.9% | $6,302/mo | −$2,330/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 Nov 9, 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 |
|---|---|---|---|---|---|---|
| 2024 | —(BIR20-008443) | ADU · Renter | — | 1 (Jan 27, 2021) | — | — |
| 2023 | —(BIR20-008443) | ADU · Renter | — | 1 (Jan 27, 2021) | — | — |
| 2022 | —(BIR20-008443) | ADU · Renter | — | 1 (Jan 27, 2021) | — | — |
| 2021 | —(BIR20-008443) | ADU · Renter | — | 1 (Jan 27, 2021) | — | — |
| 2020 | —(CDSU20-00052) | ADU · Renter | 1 (Aug 11, 2020) | — | — | — |
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: project (parcel) · Retrieved Nov 9, 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 Nov 9, 2026
0.31 acres
Assessor's classification for assessment purposes. This is not zoning.
5427 MARTIS CT
Source: Contra Costa County Assessor / Department of Information Technology, Assessment Parcels · Geography: parcel · Retrieved Nov 9, 2026
County map with assessor parcel maps and zoning. Search parcel 435-100-033.
Search by parcel number 435-100-033 (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.