Mill Valley 94941 · Tamalpais · APN 200-173-23 · Unincorporated Marin
Since October 2024 within ½ mile: 1 homes completed, 6 permitted, 4 proposed or in review; 2 demolitions.
13 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.
367 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 RSP-2 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 6.7 yr (first record Feb 11, 2020), with no completion or new permit record in 6.7 yr. · $39,972 declared valuation
Permit issued and active for 12.4 yr (first record Jun 2, 2014), with no completion or new permit record in 12.3 yr. · $400 declared valuation
Permit issued and active for 12.4 yr (first record Jun 10, 2014), with no completion or new permit record in 12.3 yr. · $12,500 declared valuation
Permit issued and active for 12.1 yr (first record Sep 29, 2014), with no completion or new permit record in 11.3 yr. · 1 unit · $600,000 declared valuation
Permit issued and active for 10.2 yr (first record Aug 15, 2016), with no completion or new permit record in 9.9 yr. · 1 unit · $900,000 declared valuation
Permit issued and active for 7.5 yr (first record May 14, 2019), with no completion or new permit record in 7.4 yr. · $10,000 declared valuation
Nearby roof replacement (546 Fairview Ave): First appeared in published agency feed
Record B48831 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff 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)
351 N Ferndale Ave · $25,000 valuation
Records span May 26, 2026 to Sep 1, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
328 Melrose Ave (Adu 328a) · 1 unit · $100,000 valuation
Records span Sep 12, 2024 to Aug 26, 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)
916 Valley View Ln · 1 unit · $5,000 valuation
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
81 Skyline Ter · 1 unit · $85,000 valuation
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)
526 Alta Way · 1 unit · $550,000 valuation
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
934 N Vernal Ave (A D U 934 A) · 1 unit · $300,000 valuation
Records span Sep 22, 2025 to Mar 10, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
812 Chamberlain Ct · 1 unit
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
375 N Ferndale Ave · $5,000 valuation
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Annual ZIP 94941 home-value index checkpoint
Changed from $2,042,452 in September 2024 to $1,980,059 in September 2025.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94941 (not a parcel appraisal)
929 Alturas Way (A D U 929 A) · 1 unit · $150,000 valuation
Records span Jan 31, 2025 to Jun 12, 2025 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
1123 W California Ave (Adu 1123a) · 1 unit · $150,000 valuation
Records span Oct 7, 2024 to Mar 7, 2025 (1 permit).
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 6.7 yr (first record Feb 11, 2020) with no new permit activity recorded in 6.7 yr.
Active in "Applied" for 3.2 yr (first record Aug 10, 2023) with no new permit activity recorded in 3.2 yr. High-impact scale (1 housing unit, $975,000 declared valuation across 1 permit).
Active in "Issued" for 10.2 yr (first record Aug 15, 2016) with no new permit activity recorded in 9.9 yr. High-impact scale (1 housing unit, $900,000 declared valuation across 1 permit).
Active in "Entitled" for 5.6 yr (first record Apr 5, 2021) with no new permit activity recorded in 5.6 yr.
Active in "Issued" for 5.5 yr (first record Apr 29, 2021) with no new permit activity recorded in 4.5 yr.
Active in "Issued" for 12.4 yr (first record Jun 2, 2014) with no new permit activity recorded in 12.3 yr.
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 ($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.
IssuedFeb 11, 2020 – Feb 11, 2020
We group related permits and State housing reports into projects. That grouping is our inference, not an official record.
Rmdl Fire Dam; Bumpout For Closets On 2nd Fl, Into Existing Liv Sp; Repl /Add Wndws, 2nd Fl; Reroof; Gas Insert T.D. 11-3-20
inspect wiring for fire damage and make safe for power to be turned on — Replace Circuits / Outlets
Interior Demo For Asbestos Abatement And Fire Debris
Rf Mtd P V Sys 2.86 K W - Express ***Expired
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
0.17 acres
Assessor's classification for assessment purposes. This is not zoning.
1011 TRILLIUM LN
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Oct 28, 2026
Search by parcel number 200-173-23. Assessed value is not market value.
Search by parcel number 200-173-23 (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.