4183 Foster Ln
El Sobrante 94803 · Unincorporated Contra Costa · Coordinates: 37.96959, -122.31221
Parcel & Assessor
- Lot size:
- 8,287 sq ft (0.19 ac)
- Assessor use:
- Single Family, 1 residence on 1 site, with or without
- Tax rate area:
- 85004
- Addresses on lot:
- 4183 FOSTER LN
Zoning & Land Use
R-6 — Single Family Residential (Unincorporated Contra Costa)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R-6 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R-6, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R-6, a single-family residential zone. The lot is 8,287 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Not in a State-mapped fire hazard severity zone
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06013C0231G, effective March 21, 2017
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $633,000 – $857,000 · Status: Off market
HUD Small Area FMR (ZIP 94803) · FY 2026
Studio $2,020 · 1BR $2,240 · 2BR $2,740 · 3BR $3,500 · 4BR $4,150
Nearby Activity (½ mile radius, since —)
8 active or recent development projects (8 housing units across completed, permitted, and pipeline stages) and 0 total building permits recorded within ½ mile.
Developments Deserving Closer Investigation & Active Area Builders
- New home (Entitled)On this parcel
Active in "Entitled" for 5.1 yr (first record Sep 27, 2021) with no new permit activity recorded in 5.1 yr.
- Balmore Court (Entitled)0.28 mi SE
Active in "Entitled" for 5.9 yr (first record Dec 14, 2020) with no new permit activity recorded in 5.9 yr. High-impact scale (33 housing units across 0 permits).
- New home (Entitled)480 ft E
Active in "Entitled" for 18 mo (first record May 8, 2025) with no new permit activity recorded in 18 mo.
- New home (Entitled)0.19 mi E
Active in "Entitled" for 5.5 yr (first record May 7, 2021) with no new permit activity recorded in 5.5 yr.
Permit & Project History on This Parcel (0 permits, 2 grouped projects)
No building permits recorded on this parcel in our dataset.
State HCD Housing Element APR records on this parcel: 2 entries (report years 2021, 2022).