Mill Valley 94941 · Tamalpais · APN 050-252-20 · Unincorporated Marin
Since October 2024 within ½ mile: 1 homes completed, 13 permitted, 10 proposed or in review; 1 demolition.
25 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.
576 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.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: permits located by parcel, ½ mile radius · Retrieved Oct 28, 2026
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 28, 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-B1 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 5.3 yr (first record Jun 21, 2021), with no completion or new permit record in 4.1 yr. · $15,000 declared valuation
Permit issued and active for 6.9 yr (first record Dec 16, 2019), with no completion or new permit record in 6.2 yr. · $200,000 declared valuation
Permit issued and active for 7.2 yr (first record Aug 13, 2019), with no completion or new permit record in 5.9 yr. · 1 unit · $600,000 declared valuation
Permit issued and active for 6 yr (first record Oct 13, 2020), with no completion or new permit record in 5.7 yr. · 1 unit · $150,000 declared valuation
In "Entitled" for 5.6 yr (since Mar 31, 2021), with no new permit record in 5.6 yr. · 1 unit
Permit issued and active for 5.7 yr (first record Mar 1, 2021), with no completion or new permit record in 5.2 yr. · 1 unit · $25,000 declared valuation
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
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)
543 Northern Ave · 1 unit · $188,000 valuation
Records span Dec 30, 2025 to Jun 17, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
3 Leo Ln · 1 unit
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)
384 Woodside Ave · 1 unit · $275,000 valuation
Records span Oct 25, 2024 to Apr 20, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
522 Northern Ave (A D U 523 Shasta Ave) · 1 unit · $150,000 valuation
Records span Sep 3, 2025 to Apr 16, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
215 Gibson Ave · 1 unit · $225,000 valuation
Records span Jul 15, 2025 to Dec 22, 2025 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
359 S Morning Sun Ave · 1 unit · $471,240 valuation
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
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 ($21,800/yr) + local voter-approved bond debt ($3,270/yr) + fixed direct levies/Mello-Roos ($450/yr).
Mapped hazard zone insurance context on this parcel:
−$124,412/yr
Cash needed: $479,600
NOI: $7,868/yr
P&I: $11,023/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 | −$10,822/mo | -27.1% | $18,739/mo | −$10,863/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $3,950/mo | −$10,368/mo | -25.9% | $17,345/mo | −$10,185/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 | −$10,107/mo | -25.3% | $16,942/mo | −$9,669/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.
IssuedJun 21, 2021 – Oct 3, 2022
We group related permits and State housing reports into projects. That grouping is our inference, not an official record.
Decommission Cell Site - Remove Sprint Wireless Equipment; Patch Roof
Seismic Retrofit, Foundations, Interior Remod, New S C B A Compressor
Installation Of New Multi-Horn Outdoor Siren
Demo/Decomission Cell Site
Replace Wndw In Kind & Sliding Doors.
Interior Commercial Remodel, Windows, Accessibility Upgrades (Barrier Removal Project)*** Ext To 3/06/20***Expired T.D. 3/16/15
(50) Replace Antennas, Install Faux Chimney And Equipment Cabinets And Electrical T.D 03/14/14
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel (APN) · Retrieved Oct 28, 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.
No housing activity reported to the State for this parcel (2018–2025 reports).
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 28, 2026
0.28 acres
Assessor's classification for assessment purposes. This is not zoning.
309 POPLAR ST
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Oct 28, 2026
Search by parcel number 050-252-20. Assessed value is not market value.
Search by parcel number 050-252-20 (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.