Mill Valley 94941 · Strawberry · APN 043-370-09 · Unincorporated Marin
Zoned RMP-4-BFC in Unincorporated Marin with likely ministerial ADU eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,280,000 ($2,006,000–$2,554,000).
Zone RMP-4-BFC allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
On-parcel permit history is indexed through Feb 1, 2022, 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)
43 substantial renovation & housing permits over 24 months (28.4 per 1,000 parcels vs. 16.4 citywide baseline) (#1 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Strawberry)
Automated synthesis of indexed municipal, county, state, and federal public records — informational context only, not a formal appraisal, survey, or legal/tax determination.
Since November 2024 within ½ mile: 3 permitted; 1 demolition.
4 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.
88 permits within ½ mile since November 2024
$2,280,000
Benchmark range: $2,006,000 – $2,554,000
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)
Closest lead: New home (0.25 mi NW, entitled). Inspect timeline history before assuming near-term completion.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · HCD APR (½-mile radius)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,223/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector
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 Nov 13, 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 Nov 13, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the State Responsibility Area (effective 2024-04-01) (retrieved Nov 9, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the Local Responsibility Area (map dated 2025-03-24) (retrieved Nov 9, 2026) · FEMA, National Flood Hazard Layer — flood hazard zones (retrieved Nov 9, 2026) · FEMA, National Flood Hazard Layer — FIRM panels (retrieved Nov 9, 2026) · California Geological Survey, Alquist-Priolo Earthquake Fault Zones (retrieved Nov 9, 2026) · Zoning classes: our classification of RMP-4-BFC as multifamily 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 12.9 yr (first record Dec 30, 2013), with no completion or new permit record in 12.6 yr. · 1 unit · $700,000 declared valuation
Permit issued and active for 12.9 yr (first record Dec 11, 2013), with no completion or new permit record in 12.3 yr. · 1 unit · $600,000 declared valuation
Permit issued and active for 12 yr (first record Nov 5, 2014), with no completion or new permit record in 12 yr. · $10,000 declared valuation
In "Applied" for 11.5 yr (since May 6, 2015), with no new permit record in 11.5 yr. · 1 unit · $425,000 declared valuation
Permit issued and active for 9.6 yr (first record Apr 13, 2017), with no completion or new permit record in 9.5 yr. · $55,000 declared valuation
Permit issued and active for 7.3 yr (first record Jul 17, 2019), with no completion or new permit record in 7.3 yr. · $5,000 declared valuation
Nearby addition (adds square footage) (6 Yellow Ferry Dock): First appeared in published agency feed
Record 94628 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby windows / doors / siding (145 Great Circle Dr): First appeared in published agency feed
Record B48901 · 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)
4 Heron Dr · 1 unit · $225,000 valuation
Records span Sep 2, 2025 to Dec 3, 2025 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
2 Nina Ct · 1 unit · $56,460 valuation
Records span Dec 9, 2022 to Oct 24, 2025 (2 permits).
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)
171 Great Cir Dr · $8,000 valuation
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
50 Great Cir Dr · 1 unit · $205,325 valuation
Records span Feb 18, 2025 to Jun 27, 2025 (1 permit).
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 $2,038,275 in September 2023 to $2,042,452 in September 2024.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94941 (not a parcel appraisal)
Annual ZIP 94941 home-value index checkpoint
Changed from $2,149,518 in September 2022 to $2,038,275 in September 2023.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94941 (not a parcel appraisal)
57 Issaquah Dock · 1 unit · $475,000 valuation
Records span Nov 7, 2022 to Mar 30, 2023 (1 permit).
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 $1,944,714 in September 2021 to $2,149,518 in September 2022.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94941 (not a parcel appraisal)
Electrical / panel permit issued (B28492)
Recorded status: Issued
-Add manual transfer switch and 30A inlet at exterior of Garage for 4 Circuit transfer switch — New Circuits / Outlets · Declared valuation: $1,958 · Contractor: Divine Electric
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
Electrical / panel permit application filed (B28492)
Current status: Issued
-Add manual transfer switch and 30A inlet at exterior of Garage for 4 Circuit transfer switch — New Circuits / Outlets · Declared valuation: $1,958 · Contractor: Divine Electric
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
HVAC / heat pump permit application filed (B28048)
Current status: Issued
Change-Out and install (2) new high furnace and air conditioner — Replace Mechanical Appliance · Declared valuation: $35,000 · Contractor: Building Efficiency Inc
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
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 →In "Entitled" for 5.1 yr (since Sep 30, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
In "Applied" for 15 mo (since Aug 14, 2025), exceeding the 55d median and 261d 90th percentile for demolition permits in Unincorporated Marin (n=130).
In "Applied" for 11.5 yr (since May 6, 2015), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Active in "Issued" for 3.9 yr (first record Dec 9, 2022) with no new permit activity recorded in 13 mo.
Active in "Issued" for 9.6 yr (first record Apr 13, 2017) with no new permit activity recorded in 9.5 yr.
Active in "Issued" for 6.6 yr (first record Apr 1, 2020) with no new permit activity recorded in 6.5 yr.
Substantial improvements (additions, interior remodels, ADUs, commercial TI, and new builds) across 1,512 parcels
+52.9% YoY
City baseline: 16.4 / 1k
43 in trailing 24m
Includes 8 ADUs
| Builder / contractor | Primary specialty | Here / ½ mi | ½ mi valuation | Citywide 24m trend |
|---|---|---|---|---|
| San Francisco Investment | New garage / accessory structure | 1 on parcel2 in ½ mi | $85,000 | 0 vs 0 prior |
| Building Efficiency | HVAC / heat pump | 1 on parcel1 in ½ mi | $35,000 | 0 vs 0 prior |
| Sustainable Living Builders | Roof replacement | 1 on parcel1 in ½ mi | $27,530 |
| Permit category | Sample (n) | 25th pct | Median (50th) | 75th pct | 90th pct | Recent 24m median |
|---|---|---|---|---|---|---|
| New single-family home | 121 | 166d | 253d | 456d | 686d | 211d(vs 273d prior) |
| New multifamily / condos / mixed-use | 21 | 272d | 292d | 293d | 313d | 293d(vs 197d prior) |
| New garage / accessory structureOn this parcel | 356 | 104d | 164d | 294d | 485d | 159d(vs 205d prior) |
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 ($22,800/yr) + local voter-approved bond debt ($3,420/yr) + fixed direct levies/Mello-Roos ($450/yr).
Insurance & hazard context:
Model adding a backyard ADU or garage conversion under California's Prop 13 blended new-construction assessment (existing house & land tax base stays intact; only ADU build cost is assessed) and SB 13 impact-fee rules.
−$130,309/yr
Cash needed: $501,600
NOI: $8,038/yr
P&I: $11,529/mo
For $0/mo net cash flow
At $3,950/mo gross 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 | −$11,313/mo | -27.1% | $19,425/mo | −$11,351/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $3,950/mo | −$10,859/mo | -26.0% | $17,980/mo | −$10,673/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 | −$10,599/mo | -25.4% | $17,562/mo | −$10,157/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.
-Add manual transfer switch and 30A inlet at exterior of Garage for 4 Circuit transfer switch — New Circuits / Outlets
Change-Out and install (2) new high furnace and air conditioner — Replace Mechanical Appliance
Removal of the current flat roof, installation of Polyglass 2 ply roofing system, 2680 square feet. — ReRoofing
Remove Stair; Add Elevator
INSTALLING ELECTRIC CAR CHARGER — EV Charging Station
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel (APN) · Retrieved Nov 13, 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 Nov 9, 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 Nov 13, 2026
0.34 acres
Assessor's classification for assessment purposes. This is not zoning.
23 HERON DR
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Nov 13, 2026
Search by parcel number 043-370-09. Assessed value is not market value.
Search by parcel number 043-370-09 (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.
| Divine Electric | Electrical / panel | 1 on parcel1 in ½ mi | $1,958 | 2 vs 1 prior |
| Evcharge4u | EV charger | 1 on parcel1 in ½ mi | $1,674 | 0 vs 0 prior |
| Lek Enterprises Recent nearby: 2 Harbor Point Dr (Mar 6, 2023) | Remodel / interior alteration | 29 in ½ mi | $961,400 | 0 vs 11 prior−100% |
| Owner Builder Recent nearby: 171 Great Circle Dr (Sep 12, 2025) | Remodel / interior alteration | 20 in ½ mi | $3,687,200 | 226 vs 240 prior−6% |
| Owner Recent nearby: 58 Great Circle Dr (Aug 7, 2019) | Remodel / interior alteration | 12 in ½ mi | $420,850 | 25 vs 15 prior+67% |
| Solarports Development Recent nearby: 475 E Strawberry Dr (Feb 27, 2023) | New garage / accessory structure | 5 in ½ mi | $366,850 | 0 vs 5 prior |
| G Family Recent nearby: 50 Great Circle Dr (Jun 27, 2025) | Remodel / interior alteration | 3 in ½ mi | $440,325 | 13 vs 8 prior+63% |
| Accessory dwelling unit (new or conversion) | 298 | 120d | 204d | 331d | 549d | 214d(vs 181d prior) |
| Addition (adds square footage) | 316 | 103d | 160d | 249d | 440d | 157d(vs 167d prior) |
| Remodel / interior alteration | 1,054 | 36d | 83d | 148d | 266d | 112d(vs 77d prior) |
| Commercial tenant improvement | 81 | 99d | 148d | 233d | 443d | 152d(vs 150d prior) |
| EV chargerOn this parcel | 482 | 0d | 0d | 0d | 0d | 0d |
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Computed from issued permits with recorded application and issuance dates over the trailing 60 months. Categories with fewer than 20 permits are excluded.