Antioch 94509 · APN 066-137-010-6 · Antioch
Located in Antioch and zero mapped flood, fire, or fault hazard overlaps; benchmark value $529,000 ($450,000–$608,000).
Estimated range $450,000–$608,000 derived from area zhvi + acs + permit benchmark and 5,093 sq ft lot geometry.
Source: ZIP 94509 Zillow Home Value Index ($536,330, September 2026) (Data provided by Zillow)
all of the lot of the parcel intersects Zone X: minimal flood hazard. Outside mandatory federal SFHA insurance rules, but check local drainage and finished-floor requirements.
Source: FEMA National Flood Hazard Layer (parcel polygon)
We could not verify a GIS base zone at this parcel centroid. Confirm zoning and allowable density directly with Antioch planning.
Source: Antioch GIS zoning registry
Automated synthesis of indexed municipal, county, state, and federal public records — informational context only, not a formal appraisal, survey, or legal/tax determination.
Since — within ½ mile: 74 homes completed, 15 permitted.
89 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.
$529,000
Benchmark range: $450,000 – $608,000
Closest lead: New home (0.27 mi S, issued). Inspect timeline history before assuming near-term completion.
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) · HCD APR (½-mile radius)
Permit counts and nearby activity on this page may omit municipal counter records. Request a parcel permit report directly from the local building department.
Source: Source coverage registry (Antioch)
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 Antioch, 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 Antioch'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)
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.
Latest published Zillow Home Value Index (ZHVI) update
Changed from $541,757 in September 2025 to $536,330 in September 2026.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94509 (not a parcel appraisal)
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
1 unit
Records span Dec 6, 2024 to Dec 15, 2025 (0 permits).
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
1 unit
Records span Dec 6, 2024 to Dec 15, 2025 (0 permits).
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
1 unit
Records span Dec 6, 2024 to Dec 9, 2025 (0 permits).
Source: City of Richmond Planning & Building, PermitTrak (eTRAKiT permits, 1992 to April 2025) & HCD APR (grouped project within ½ mile)
1 unit
Records span Dec 6, 2024 to Dec 9, 2025 (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)
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)
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 94509 home-value index checkpoint
Changed from $577,385 in September 2024 to $541,757 in September 2025.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94509 (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)
Cross-referenced intelligence from our historical development graph—connecting parcels, permits, entity-resolved builders, empirical review-time distributions, and neighborhood renovation trends.
Explore full Antioch development graph →Active in "Issued" for 16 mo (first record Jul 28, 2025) with no new permit activity recorded in 16 mo.
Active in "Issued" for 13 mo (first record Oct 22, 2025) with no new permit activity recorded in 13 mo.
Active in "Issued" for 13 mo (first record Oct 22, 2025) with no new permit activity recorded in 13 mo.
Active in "Issued" for 13 mo (first record Oct 22, 2025) with no new permit activity recorded in 13 mo.
Active in "Issued" for 13 mo (first record Oct 22, 2025) with no new permit activity recorded in 13 mo.
Active in "Issued" for 13 mo (first record Oct 22, 2025) with no new permit activity recorded in 13 mo.
HUD Small Area Fair Market Rent · ZIP 94509
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 ($8,025/yr) + local voter-approved bond debt ($1,445/yr) + fixed direct levies/Mello-Roos ($450/yr).
Insurance & hazard context:
Model adding a backyard ADU or garage conversion under California's Prop 13 blended new-construction assessment (existing house & land tax base stays intact; only ADU build cost is assessed) and SB 13 impact-fee rules.
Statutory notes: Under CA Gov. Code § 66324 (SB 13), local agencies cannot impose development impact fees on ADUs under 750 sq ft (plan-check, school district fees ≥500 sq ft, and utility connection fees still apply). Under CA Rev. & Tax. Code § 71, building an ADU triggers a supplemental assessment on the new construction value without reassessing the existing dwelling or land. Newly built ADUs also carry a rolling 15-year exemption from statewide AB 1482 rent caps from certificate of occupancy.
−$22,884/yr
Cash needed: $184,725
NOI: $28,660/yr
P&I: $4,295/mo
For $0/mo net cash flow
At $4,425/mo gross 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 | $4,071/mo | −$2,415/mo | -15.7% | $7,443/mo | −$2,319/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $4,425/mo | −$1,907/mo | -12.4% | $6,889/mo | −$1,559/mo |
| Optimistic (cap-limited) | +6% starting rent, 3% vacancy, 4.5%/yr rent growth (capped by AB 1482 ceiling of 8.6%/yr) | $4,691/mo | −$1,615/mo | -10.5% | $6,729/mo | −$981/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.
No housing activity reported to the State for this parcel (2018–2025 reports).
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: project (parcel) · Retrieved Nov 9, 2026 · From Antioch'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
0.12 acres
Assessor's classification for assessment purposes. This is not zoning.
609 L ST
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 066-137-010.
Search by parcel number 066-137-010 (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.