316 Rydal Ave
Mill Valley 94941 · Homestead · Unincorporated Marin · Coordinates: 37.89245, -122.54408
Executive Verdict · Public-Records Synthesis
Zoned R1 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 $2,210,000 ($1,945,000–$2,475,000).
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 9,801 sq ft lot. Local precedent is active with 5 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ 5 documented municipal building permits on file
On-parcel permit history is indexed through Mar 10, 2026, 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)
- ✓ Above-average reinvestment in Homestead
22 substantial renovation & housing permits over 24 months (20.7 per 1,000 parcels vs. 16.4 citywide baseline) (#2 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Homestead)
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
Other (170542): Issued after 2 mo — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,560).
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: New home at 210 Brabo Ter (0.18 mi E, 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)
Parcel & Assessor
- Lot size:
- 9,801 sq ft (0.23 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 316 RYDAL AVE
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 9,801 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: $1,945,000 – $2,475,000 · 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
- Other (170542) (Issued)On this parcel
Issued after 2 mo — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,560).
- New home at 210 Brabo Ter (Issued)0.18 mi E
Active in "Issued" for 3.1 yr (first record Oct 12, 2023) with no new permit activity recorded in 2.6 yr. High-impact scale (1 housing unit, $850,000 declared valuation across 1 permit).
- New home at 204 Reed St (Issued)0.19 mi NE
Active in "Issued" for 4.3 yr (first record Aug 5, 2022) with no new permit activity recorded in 3.5 yr. High-impact scale (1 housing unit, $950,000 declared valuation across 1 permit).
- New home at 164 Linden Ln (Issued)0.27 mi NE
Active in "Issued" for 8.1 yr (first record Oct 1, 2018) with no new permit activity recorded in 7.5 yr. High-impact scale (1 housing unit, $780,000 declared valuation across 3 permits).
Entity-resolved builders & contractors in ½ mile: Sonoma County Sunrooms (1 on parcel, 1 in ½ mi · Other); Piscatelli (1 on parcel, 1 in ½ mi · Roof replacement); Thompson Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Plumbing Repair Specialist (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Owner Builder (70 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B46147 | Roof replacement | Issued | Iss. Mar 10, 2026 | $24,200 | ReRoofing |
| B38525 | Electrical / panel | Issued | Iss. Jun 26, 2024 | $2,500 | REPLACMENT OF ELECTRIC SERVICE WITH NEW 100AMP SERVICE. NEW PANEL TO BE INSTALLED IN THE EXISTING LOCATION. — Service Up… |
| 170542 | Other | Issued | Iss. Feb 2, 2022 | $31,000 | Replace Deck & Stairs |
| 168498 | New garage / accessory structure | Issued | Iss. Jun 15, 2021 | $39,000 | Replace Sunroom |
| 144311 | Plumbing / water heater / sewer | Issued | Iss. Sep 30, 2014 | $2,000 |