5 Maxwell Ln
Mill Valley 94941 · Almonte · Unincorporated Marin · Coordinates: 37.89095, -122.53209
Executive Verdict · Public-Records Synthesis
Zoned R1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,240,000 ($1,971,000–$2,509,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 15,725 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
- ✓ 3 documented municipal building permits on file
On-parcel permit history is indexed through May 11, 2025, letting you verify roof, HVAC, electrical, or structural work against seller disclosures.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
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)
- ! Delayed or open permit activity on this parcel
Other (75616): Pending in review for 11.1 yr — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,562).
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: 2 new homes (0.17 mi N, issued). Inspect timeline history before assuming near-term completion.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · HCD APR (½-mile radius)
- ! Year 1 Prop 13 tax reset (~$26,210/yr at $2,240,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,184/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector
Parcel & Assessor
- Lot size:
- 15,725 sq ft (0.36 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 5 MAXWELL LN
Zoning & Land Use
R1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1, a single-family residential zone. The lot is 15,725 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 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: $1,971,000 – $2,509,000 · 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
Nearby Activity (½ mile radius, since November 2024)
13 active or recent development projects (11 housing units across completed, permitted, and pipeline stages) and 408 total building permits recorded within ½ mile.
- New construction4 permits (1 units)
- Adds housing (ADU)9 permits (9 units)
- Demolition2 permits
- Additions & renovations35 permits
- Building systems278 permits
- Repairs15 permits
- Other65 permits
Developments Deserving Closer Investigation & Active Area Builders
- Other (75616) (Applied)On this parcel
Pending in review for 11.1 yr — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,562).
- 2 new homes (Issued)0.17 mi N
Active in "Issued" for 5.7 yr (first record Mar 1, 2021) with no new permit activity recorded in 5.7 yr. High-impact scale (2 housing units, 1 deed-restricted affordable across 0 permits).
- 2 new homes (Issued)0.17 mi N
Active in "Issued" for 5.7 yr (first record Mar 1, 2021) with no new permit activity recorded in 5.7 yr. High-impact scale (2 housing units, 1 deed-restricted affordable across 0 permits).
- New home (Issued)0.17 mi N
Active in "Issued" for 7.5 yr (first record May 10, 2019) with no new permit activity recorded in 7.4 yr. High-impact scale (1 housing unit, 1 deed-restricted affordable across 0 permits).
Entity-resolved builders & contractors in ½ mile: Gramajo Roofing (1 on parcel, 1 in ½ mi · Roof replacement); All Seasons Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Owner Builder (86 in ½ mi · Remodel / interior alteration); Owner (40 in ½ mi · Remodel / interior alteration); Miette (6 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (3 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B42359 | Roof replacement | Issued | Iss. May 11, 2025 | $25,000 | REMOVE EXISTING ROOF MEMBRANE. INSTALL NEW 3 PLY CLASS A TORCH DOWN ROOF SYSTEM — ReRoofing |
| 75616 | Other | Applied | App. Oct 5, 2015 | $18,000 | Replace (E) Deck***Expired T.D. 10/28/15 Plans Tossed 1/23/18 |
| 148171 | Roof replacement | Issued | Iss. Jul 28, 2015 | $18,000 | Reroof***Expired |