4222 Foster Ln
El Sobrante 94803 · Unincorporated Contra Costa · Coordinates: 37.96959, -122.31036
Parcel & Assessor
- Lot size:
- 9,546 sq ft (0.22 ac)
- Assessor use:
- Single Family, 1 residence on 1 site, with or without
- Tax rate area:
- 85004
- Addresses on lot:
- 4222 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 9,546 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: $640,000 – $866,000 · 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 November 2024)
9 active or recent development projects (9 housing units across completed, permitted, and pipeline stages) and 1 total building permits recorded within ½ mile.
- Other1 permit
Developments Deserving Closer Investigation & Active Area Builders
- New home (Entitled)On this parcel
Active in "Entitled" for 18 mo (first record May 8, 2025) with no new permit activity recorded in 18 mo.
- Balmore Court (Entitled)0.24 mi S
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 commercial building at 4555 Hilltop Dr (Applied)0.49 mi N
Active in "Applied" for 2 yr (first record Oct 31, 2024) with no new permit activity recorded in 2 yr. High-impact scale ($2,006,000 declared valuation across 1 permit).
- New home (Entitled)480 ft W
Active in "Entitled" for 5.1 yr (first record Sep 27, 2021) with no new permit activity recorded in 5.1 yr.
Permit & Project History on This Parcel (0 permits, 1 grouped projects)
No building permits recorded on this parcel in our dataset.
State HCD Housing Element APR records on this parcel: 1 entry (report years 2025).