1251 Lattie Ln
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.88825, -122.54604
Executive Verdict · Public-Records Synthesis
Zoned RSP-1 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 $2,178,000 ($1,917,000–$2,439,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned RSP-1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 6,490 sq ft lot. Local precedent is active with 4 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$96,534 contributory est.)
Public building records show issued construction/renovation work on this parcel (7 total permits, latest Mar 5, 2026).
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. 16.4 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 (179712): Issued after 2.1 yr — slower than 90% of windows / doors / siding permits in Unincorporated Marin (median 0d, 90th pct 5d, n=1,476).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 3 slow or stalled nearby projects within ½ mile
Closest lead: New home at 560 Alta Way (0.35 mi SE, 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:
- 6,490 sq ft (0.15 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 1251 LATTIE LN
Zoning & Land Use
RSP-1 — Residential Single Family Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RSP-1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned RSP-1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned RSP-1, a single-family residential zone. The lot is 6,490 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: $1,917,000 – $2,439,000 · 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
- New home at 560 Alta Way (Applied)0.35 mi SE
In "Applied" for 3.3 yr (since Aug 10, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $975,000 declared valuation across 1 permit).
- Windows / doors / siding (179712) (Issued)On this parcel
Issued after 2.1 yr — slower than 90% of windows / doors / siding permits in Unincorporated Marin (median 0d, 90th pct 5d, n=1,476).
- General repair (179711) (Issued)On this parcel
Issued after 2.1 yr (9.1× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
- Other (88755) (Applied)On this parcel
Pending in review for 5.3 yr — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,560).
Entity-resolved builders & contractors in ½ mile: Hadley General Contractors (3 on parcel, 3 in ½ mi · General repair); Semper Solaris Construction (1 on parcel, 1 in ½ mi · Solar / battery storage); Premier Construction (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Tesla Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Owner Builder (41 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (7 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 181241 | Remodel / interior alteration | Issued | Iss. Mar 5, 2026 | $150,000 | Reloc Kit, Fam Rm; Add Powd Rm; Rmv Ext Stone Cladding; Deck Rail & Deck Ret Wall; Add/Repl Windows Incl Gar; Soil Shor … |
| 179712 | Windows / doors / siding | Issued | Iss. Jul 23, 2025 | $340,000 | Decks; Foundation; Siding; Windows/Doors |
| 179711 | General repair | Issued | Iss. Jul 23, 2025 | $10,000 | South West Stepped Concrete Ret Wall |
| B27355 | Solar / battery storage | Issued | Iss. Oct 8, 2021 | $26,400 | INSTALLING/ADDING 2 -(N) TESLAPOWERWALL2 BATTERY BACKUP SYSTEMS & 1-(N)TESLAGATEWAY2 GATEWAY BEING ADDED ON TO AN (E)3.6… |
| 88755 | Other | Applied |