Mill Valley 94941 · Tamalpais · APN 049-063-20 · Unincorporated Marin
Zoned R1-B2 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,181,000 ($1,919,000–$2,443,000).
Zoned R1-B2 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 10,367 sq ft lot. Local precedent is active with 6 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
Public building records show issued construction/renovation work on this parcel (7 total permits, latest Oct 11, 2024).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
50 substantial renovation & housing permits over 24 months (20.5 per 1,000 parcels vs. 16.4 citywide baseline) (#3 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Tamalpais)
Automated synthesis of indexed municipal, county, state, and federal public records — informational context only, not a formal appraisal, survey, or legal/tax determination.
$2,181,000
Benchmark range: $1,919,000 – $2,443,000
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)
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)
Closest lead: New home at 560 Alta Way (0.15 mi N, applied). 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 (~$2,128/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector
Since November 2024 within ½ mile: 1 homes completed, 11 permitted, 8 proposed or in review; 1 demolition.
21 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.
546 permits within ½ mile since November 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 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 R1-B2 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.
In "Entitled" for 5.6 yr (since Apr 5, 2021), with no new permit record in 5.6 yr. · 1 unit
In "Applied" for 5.2 yr (since Sep 13, 2021), with no new permit record in 5.2 yr. · 1 unit · $398,430 declared valuation
Permit issued and active for 5.7 yr (first record Feb 18, 2021), with no completion or new permit record in 5 yr. · 1 unit · $240,000 declared valuation
In "Applied" for 5.2 yr (since Sep 7, 2021), with no new permit record in 4.9 yr. · 1 unit · $200,000 declared valuation
In "Entitled" for 4.8 yr (since Jan 19, 2022), with no new permit record in 4.8 yr. · 1 unit
Permit issued and active for 5.5 yr (first record Apr 29, 2021), with no completion or new permit record in 4.5 yr. · 1 unit · $75,000 declared valuation
Nearby other (4 Leo Ln): First appeared in published agency feed
Record B49100 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (403 Marin Ave): First appeared in published agency feed
Record B49090 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby accessory dwelling unit (new or conversion) (3 Leo Ln (Aka 3 A)): First appeared in published agency feed
Record 182940 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (529 Brookline Way): First appeared in published agency feed
Record B49083 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby roof replacement (4 Leo Ln): First appeared in published agency feed
Record B49080 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (1075 Erica Rd): First appeared in published agency feed
Record B49072 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (1217 Waterview Dr): First appeared in published agency feed
Record 94643 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Record 94306 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (250 Loring Ave): First appeared in published agency feed
Record B48929 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (908 Vernal Way): First appeared in published agency feed
Record B49065 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (1212 El Cide Ct): First appeared in published agency feed
Record B49060 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (386 Pinehill Rd): First appeared in published agency feed
Record B48997 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (552 Shoreline Hwy): First appeared in published agency feed
Record B48968 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby windows / doors / siding (875 Chamberlain Ct): First appeared in published agency feed
Record B48958 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
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
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 "Applied" for 3.3 yr (since Aug 10, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $975,000 declared valuation across 1 permit).
Active in "Issued" for 18 mo (first record May 12, 2025) with no new permit activity recorded in 15 mo. High-impact scale (1 housing unit, $955,000 declared valuation across 1 permit).
Active in "Issued" for 2.9 yr (first record Dec 21, 2023) with no new permit activity recorded in 19 mo. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
Active in "Issued" for 3.3 yr (first record Jul 19, 2023) with no new permit activity recorded in 2.3 yr. High-impact scale (1 housing unit, $1,183,700 declared valuation across 2 permits).
Active in "Issued" for 6.1 yr (first record Oct 22, 2020) with no new permit activity recorded in 22 mo. High-impact scale (1 housing unit, $980,000 declared valuation across 1 permit).
In "Applied" for 3.1 yr (since Oct 11, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Substantial improvements (additions, interior remodels, ADUs, commercial TI, and new builds) across 2,439 parcels
−7.7% YoY
City baseline: 16.4 / 1k
50 in trailing 24m
Includes 16 ADUs
| Builder / contractor | Primary specialty | Here / ½ mi | ½ mi valuation | Citywide 24m trend |
|---|---|---|---|---|
| Sunrun Installation Services | Solar / battery storage | 3 on parcel3 in ½ mi | $19,456 | 0 vs 0 prior |
| Bay Area Window Pros | Windows / doors / siding | 1 on parcel1 in ½ mi | $43,190 | 0 vs 0 prior |
| Sutter Roofing And Sheet Metal | Roof replacement | 1 on parcel1 in ½ mi | $22,000 |
| 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) |
| Accessory dwelling unit (new or conversion) | 298 | 120d | 204d | 331d | 549d | 214d(vs 181d prior) |
| Addition (adds square footage) |
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:
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.
−$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 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 | −$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.
PV SOLAR 3120W DC, 3800W AC, (8) MODULES, MAIN PANEL REPLACEMENT, EXISTING SOLAR SYSTEM INSTALLED.
• MAIN PANEL REPLACEMENT: EXISTING 100 AMP MAIN PANEL WITH HOT BUS TO BE REPLACED WITH NEW 200 AMP MAIN PANEL WITH 200 AMP MAIN BREAKER WITH 225 BUSBAR. EXISTING SOLAR SYSTEM INSTALLED.
TEAR OFF, RE ROOF, INSTALL CLASS A COMP SHINGLES, 25SQ'S — ReRoofing
3800W AC , 8 Panel Roof-Mount PV System w/ MPU
replace 10 windows and 2 doors, size for size — Non-structural Door/Window Replacement
Install 50 gallon water heater in existing location. — Replace Plumbing Fixtures(s)
2.34kw Roof-Mounted Photovoltaic - Express
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
0.24 acres
Assessor's classification for assessment purposes. This is not zoning.
865 CHAMBERLAIN CT
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Nov 13, 2026
Search by parcel number 049-063-20. Assessed value is not market value.
Search by parcel number 049-063-20 (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.
| 0 vs 0 prior |
| Solarcity Dba Tesla Energy | Solar / battery storage | 1 on parcel1 in ½ mi | $5,200 | 0 vs 0 prior |
| Oak Plumbing | Plumbing / water heater / sewer | 1 on parcel1 in ½ mi | $2,338 | 0 vs 0 prior |
| Owner Builder Recent nearby: 642 Northern Ave (Oct 19, 2026) | Remodel / interior alteration | 91 in ½ mi | $9,640,720 | 226 vs 240 prior−6% |
| Owner Recent nearby: 722 Alta Vista Rd (Jun 17, 2025) | Remodel / interior alteration | 45 in ½ mi | $2,673,594 | 25 vs 15 prior+67% |
| International Building Investment Recent nearby: 396 Pine Hill Rd #37 (May 31, 2017) | Remodel / interior alteration | 12 in ½ mi | $173,200 | 0 vs 0 prior |
| Barton Design And Constuction Recent nearby: 406 Wendy Way (Oct 21, 2022) | Remodel / interior alteration | 7 in ½ mi | $2,275,000 | 0 vs 0 prior |
| Leon Construction Recent nearby: 396 Pinehill Rd #10 (Sep 9, 2014) | Remodel / interior alteration | 7 in ½ mi | $224,000 | 0 vs 0 prior |
| 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) |
| Solar / battery storageOn this parcel | 2,977 | 0d | 0d | 0d | 2d | 0d |
| Roof replacementOn this parcel | 3,663 | 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.