Mill Valley 94941 · Tamalpais · APN 052-015-04 · Unincorporated Marin
Since October 2024 within ½ mile: 1 homes completed, 6 permitted, 11 proposed or in review; 1 demolition.
19 projects with a record in this window, grouped by us from permits and State housing reports. Units are as proposed on each project's latest record and counted at its current stage.
529 permits within ½ mile since October 2024
The map shows new construction, ADUs, demolitions, additions, and renovations. Routine systems work (roofs, HVAC, water heaters) is counted but not mapped. Unit counts are as stated on permits.
$2,360,000
Benchmark range: $2,077,000 – $2,643,000
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: permits located by parcel, ½ mile radius · Retrieved Oct 29, 2026
Public-records benchmark estimate combining Zillow Home Value Index (Data provided by Zillow), Census ACS 5-year estimates, parcel land-use/lot characteristics, and issued building permits. Not an official appraisal.
Permit counts, by the date issued (or applied, if not yet issued). Lot splits are planning cases, which we don't have.
We read public zoning and hazard maps against state law (ADUs: Gov. Code 66314; SB 9: Gov. Code 65852.21 and 66411.7). Local rules, title, tenancy history and site conditions can change the answer. Check with Unincorporated Marin's planning department before relying on it.
Sources: County of Marin GIS (MarinMap), Zoning (11 cities and unincorporated Marin) (retrieved Oct 29, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the State Responsibility Area (effective 2024-04-01) (retrieved Oct 26, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the Local Responsibility Area (map dated 2025-03-24) (retrieved Oct 26, 2026) · FEMA, National Flood Hazard Layer — flood hazard zones (retrieved Oct 26, 2026) · FEMA, National Flood Hazard Layer — FIRM panels (retrieved Oct 26, 2026) · California Geological Survey, Alquist-Priolo Earthquake Fault Zones (retrieved Oct 26, 2026) · Zoning classes: our classification of R1 as single-family residential, checked against the zone description on Oct 24, 2026
Chronological history of building permit applications and issuances, snapshot-dated status changes, State housing entitlements, surrounding development within ½ mile, and area home-value trends.
Permit issued and active for 12.6 yr (first record Mar 13, 2014), with no completion or new permit record in 12.4 yr. · 1 unit · $517,000 declared valuation
Permit issued and active for 11.7 yr (first record Feb 17, 2015), with no completion or new permit record in 11.2 yr. · $3,938,400 declared valuation
Permit issued and active for 10.4 yr (first record May 24, 2016), with no completion or new permit record in 10.3 yr. · $10,000 declared valuation
In "Applied" for 9.6 yr (since Mar 20, 2017), with no new permit record in 9.6 yr. · $250,000 declared valuation
Permit issued and active for 9.6 yr (first record Mar 28, 2017), with no completion or new permit record in 9.6 yr. · $250 declared valuation
Permit issued and active for 9.5 yr (first record Apr 11, 2017), with no completion or new permit record in 9.5 yr. · $45,000 declared valuation
Record 94571 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby new garage / accessory structure (359 Durant Way): First appeared in published agency feed
Record 182828 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby electrical / panel (240 Perry St): First appeared in published agency feed
Record B48926 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (254 Shoreline Hwy): First appeared in published agency feed
Record B48920 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (359 Durant Way): No longer present in latest agency feed
Record 94342 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby windows / doors / siding (220 Cardinal Rd): First appeared in published agency feed
Record B48903 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby roof replacement (385 Countyview Dr): First appeared in published agency feed
Record B48891 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby electrical / panel (354 Starling Rd): First appeared in published agency feed
Record B48885 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (314 Durant Way): First appeared in published agency feed
Record B48877 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
310 Tennessee Ave · 1 unit · $250,000 valuation
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Latest published Zillow Home Value Index (ZHVI) update
Changed from $1,980,059 in September 2025 to $2,181,389 in September 2026.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94941 (not a parcel appraisal)
324 Sheffield Ave · 1 unit · $80,000 valuation
Records span Jan 22, 2026 to Sep 15, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
351 Dolan Ave · 1 unit · $149,000 valuation
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
251 Marin Ave · 1 unit · $260,000 valuation
Records span Oct 28, 2025 to Jun 29, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
283 Greene St · 1 unit · $300,000 valuation
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Cross-referenced intelligence from our historical development graph—connecting parcels, permits, entity-resolved builders, empirical review-time distributions, and neighborhood renovation trends.
Explore full Unincorporated Marin development graph →Active in "Issued" for 8.1 yr (first record Sep 5, 2018) with no new permit activity recorded in 7.9 yr. High-impact scale (1 housing unit, $759,000 declared valuation across 1 permit).
Active in "Issued" for 11.7 yr (first record Feb 17, 2015) with no new permit activity recorded in 11.2 yr. High-impact scale ($3,938,400 declared valuation across 3 permits).
Active in "Issued" for 2.9 yr (first record Dec 21, 2023) with no new permit activity recorded in 18 mo. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
Active in "Issued" for 7.6 yr (first record Mar 14, 2019) with no new permit activity recorded in 7.4 yr. High-impact scale (1 housing unit, $750,000 declared valuation across 1 permit).
Active in "Issued" for 6 yr (first record Oct 29, 2020) with no new permit activity recorded in 4 yr. High-impact scale (1 housing unit, $800,000 declared valuation across 1 permit).
Active in "Applied" for 16 mo (first record Jun 13, 2025) with no new permit activity recorded in 16 mo.
Substantial improvements (additions, interior remodels, ADUs, commercial TI, and new builds) across 2,439 parcels
+0.0% YoY
City baseline: 16.5 / 1k
50 in trailing 24m
Includes 14 ADUs
HUD Small Area Fair Market Rent · ZIP 94941
HUD FY 2026 · 40th-percentile gross rentCensus ACS 5-year median gross rent (all bedroom counts combined):
Area home-value benchmarks (not an appraisal)
ZIP & neighborhood mediansUnder California Proposition 13, the seller's historical assessed value does not carry over to a buyer. On sale, the parcel is reassessed at the purchase price: 1.00% base rate ($23,600/yr) + local voter-approved bond debt ($3,540/yr) + fixed direct levies/Mello-Roos ($450/yr).
Mapped hazard zone insurance context on this parcel:
−$137,404/yr
Cash needed: $519,200
NOI: $5,798/yr
P&I: $11,933/mo
For $0/mo net cash flow
At $3,950/mo rent
| Scenario | Assumptions | Year 1 Rent | Year 1 Cash Flow | Cash-on-Cash | Break-Even Rent | Year 5 Cash Flow |
|---|---|---|---|---|---|---|
| Conservative | −8% starting rent, +3% vacancy, +3% combined maintenance/CapEx, 1.5%/yr rent growth | $3,634/mo | −$11,904/mo | -27.5% | $20,251/mo | −$11,959/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $3,950/mo | −$11,450/mo | -26.5% | $18,744/mo | −$11,282/mo |
| Optimistic (cap-limited) | +6% starting rent, 3% vacancy, 4.5%/yr rent growth (capped by AB 1482 ceiling of 8.6%/yr) | $4,187/mo | −$11,190/mo | -25.9% | $18,308/mo | −$10,766/mo |
Rental regulatory context (informational only — not legal advice):
California AB 1482 (Tenant Protection Act, Civ. Code § 1947.12) caps annual rent increases at 5% + local CPI (max 10%) on covered properties.
Finaled / completed1 unitsFeb 24, 2023 – Oct 6, 2023
We group related permits and State housing reports into projects. That grouping is our inference, not an official record.
1. REMOVE EXISTING ROOF DOWN TO THE BASE SHEATHING, INSPECT FOR DRY ROT. 2. INSTALLNEW SYNTHETIC ROOIFNG UNDERLAYMENT. 3. INSTALL NEW GAF TIMBERLINE HDZ COMPOSITION SHINGLES. — ReRoofing
Legalize & Remodel A D U - B W O P
Tear-Off & Re-Roof***Extended 1/25/19
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel (APN) · Retrieved Oct 29, 2026 · Received and issued dates come from the County of Marin. The county publishes no final or expired status, so an issued permit stays 'Issued' after the work is done.
| Report year | Project / record | Type | Entitled | Permitted | Completed | Deed-restricted |
|---|---|---|---|---|---|---|
| 2024 | —(90850) | ADU · Renter | — | 1 (Oct 6, 2023) | 1 (Jan 9, 2024) | — |
| 2023 | —(90850) | ADU · Renter | — | 1 (Oct 6, 2023) | — | — |
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: project (parcel) · Retrieved Oct 26, 2026 · From Unincorporated Marin's Housing Element Annual Progress Reports. A project can appear in several report years as it moves from entitlement to permit to completion.
Source: County of Marin GIS (MarinMap), Zoning (11 cities and unincorporated Marin) · Geography: zoning district polygon at parcel point · Retrieved Oct 29, 2026
0.20 acres
Assessor's classification for assessment purposes. This is not zoning.
323 ROSS DR; 325 ROSS DR
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Oct 29, 2026
Search by parcel number 052-015-04. Assessed value is not market value.
Search by parcel number 052-015-04 (Marin County Tax Collector)
Permits issued in unincorporated Marin in the past 48 months. Each city keeps its own records.
The official flood hazard map for this location. Our reading of it is under What could be built here.
This site does not show owner names.