822 Spring Dr
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.87644, -122.54440
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,203,000 ($1,939,000–$2,467,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 9,714 sq ft lot. Local precedent is active with 3 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$54,452 contributory est.)
Public building records show issued construction/renovation work on this parcel (6 total permits, latest May 8, 2024).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Tamalpais
50 substantial renovation & housing permits over 24 months (20.5 per 1,000 parcels vs. 16.3 citywide baseline) (#3 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Tamalpais)
Watchouts & Due Diligence
- ! Mapped flood awareness zone (Zone X: minimal flood hazard)
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)
- ! CAL FIRE High Fire Hazard Severity Zone (State Responsibility Area) (all of the lot of lot)
Located in a mapped Fire Hazard Severity Zone. Expect Chapter 7A ignition-resistant building standards, defensible-space inspections, and stricter property insurance underwriting.
Source: CAL FIRE FHSZ (map Apr 1, 2024)
- ! Delayed or open permit activity on this parcel
Windows / doors / siding (166018): Issued after 10 mo — slower than 90% of windows / doors / siding permits in Unincorporated Marin (median 0d, 90th pct 5d, n=1,477).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 5 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 875 Marin Dr (0.12 mi S, applied). Inspect timeline history before assuming near-term completion.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · HCD APR (½-mile radius)
Parcel & Assessor
- Lot size:
- 9,714 sq ft (0.22 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 822 SPRING DR
Zoning & Land Use
R1-B1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B1, a single-family residential zone. The lot is 9,714 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
- High Fire Hazard Severity Zone (State Responsibility Area) (all of the lot, map Apr 1, 2024)
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06041C0468F, effective March 16, 2016
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $1,939,000 – $2,467,000 · Status: Off market
HUD Small Area FMR (ZIP 94941) · FY 2026
Studio $2,730 · 1BR $3,270 · 2BR $3,960 · 3BR $5,060 · 4BR $5,240
Developments Deserving Closer Investigation & Active Area Builders
- Accessory dwelling unit at 875 Marin Dr (Applied)0.12 mi S
In "Applied" for 2.6 yr (since Apr 11, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). Record changed to "updated" in snapshot Nov 4, 2026.
- Windows / doors / siding (166018) (Issued)On this parcel
Issued after 10 mo — slower than 90% of windows / doors / siding permits in Unincorporated Marin (median 0d, 90th pct 5d, n=1,477).
- New home at 812 Spring Dr (Issued)290 ft SE
Active in "Issued" for 4.2 yr (first record Sep 19, 2022) with no new permit activity recorded in 3.3 yr. High-impact scale (1 housing unit, $1,006,000 declared valuation across 1 permit).
- New home at 808 Spring Dr (Issued)380 ft SE
Active in "Issued" for 4.9 yr (first record Dec 13, 2021) with no new permit activity recorded in 4.7 yr. High-impact scale (1 housing unit, $850,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Mill Valley Builders (2 on parcel, 2 in ½ mi · Remodel / interior alteration); Simple Living (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Mc Leran (1 on parcel, 1 in ½ mi · Roof replacement); Bk Krill (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Charles Electric (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer).
Permit & Project History on This Parcel (6 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 176586 | Remodel / interior alteration | Issued | Iss. May 8, 2024 | $12,500 | Remove (E) Brick Fireplace & Rebuild Chase For (N) Gas Insert, Reuse Gas Hookup |
| B28005 | Roof replacement | Issued | Iss. Dec 7, 2021 | $19,400 | Tear off main & studio roofs to solid sheeting. Re-roof with Class A Tar & Gravel Roof System (with crushed granite). — … |
| 166018 | Windows / doors / siding | Issued | Iss. Oct 20, 2020 | $20,000 | All New Struct Windows In Detached Studio - B W O P Erin Y T.D. 12/31/19 |
| 165469 | Remodel / interior alteration | Issued | Iss. Aug 18, 2020 | $60,000 | Inter. Struct Rmdl Lwr Lvl, Rmv Non Prmt Sheds And Encl Of Exstg Stairs, New Swing Drs. ***B W O P (E.Y.) T.D. 7/10/20 |
| B20207 |