San Rafael 94903 · Lucas Valley · APN 164-064-08 · Unincorporated Marin
Zoned R1-B-LV in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE high fire hazard severity zone (local responsibility area) due diligence; benchmark value $1,370,000 ($1,206,000–$1,534,000).
Zoned R1-B-LV supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 7,318 sq ft lot. Local precedent is active with 2 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
On-parcel permit history is indexed through Nov 13, 2026, 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)
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)
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: 2 permitted.
2 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.
221 permits within ½ mile since November 2024
$1,370,000
Benchmark range: $1,206,000 – $1,534,000
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 Mar 24, 2025)
Closest lead: Accessory dwelling unit at 42 Oak Mountain Ct (0.16 mi NW, 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 (~$1,350/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 14, 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 14, 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-B-LV 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 8.5 yr (first record May 29, 2018), with no completion or new permit record in 8.4 yr. · $25,000 declared valuation
In "Applied" for 5.5 yr (since Apr 30, 2021), with no new permit record in 5.5 yr. · 1 unit · $250,000 declared valuation
In "Applied" for 4.8 yr (since Jan 20, 2022), with no new permit record in 4.8 yr. · 1 unit · $75,000 declared valuation
In "Applied" for 4.4 yr (since Jun 7, 2022), with no new permit record in 4.4 yr. · $80,000 declared valuation
Permit issued and active for 3.3 yr (first record Jul 19, 2023), with no completion or new permit record in 2.5 yr. · 1 unit · $375,000 declared valuation
Permit issued and active for 3.1 yr (first record Oct 20, 2023), with no completion or new permit record in 2.4 yr. · 1 unit · $146,600 declared valuation
Other (B49061): First appeared in published agency feed
Detected between upstream data snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff window
Other permit issued (B49061)
Recorded status: Issued
Declared valuation: $25,000 · Contractor: Owner
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
Other permit application filed (B49061)
Current status: Issued
Declared valuation: $25,000 · Contractor: Owner
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
Nearby other (55 Pikes Peak Dr): First appeared in published agency feed
Record B49039 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby plumbing / water heater / sewer (14 Mt Rainier Ct): First appeared in published agency feed
Record B48988 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby roof replacement (1 Mt Palomar Ct): First appeared in published agency feed
Record B48964 · 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 $1,200,587 in September 2025 to $1,250,063 in September 2026.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94903 (not a parcel appraisal)
Electrical / panel permit issued (B48445)
Recorded status: Issued
Service Upgrade · Declared valuation: $1,500 · Contractor: I Cannan Electric
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
Electrical / panel permit application filed (B48445)
Current status: Issued
Service Upgrade · Declared valuation: $1,500 · Contractor: I Cannan Electric
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
150 Mt Whitney Ct (Adu 150a) · 1 unit · $250,000 valuation
Records span Oct 22, 2025 to Apr 10, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Annual ZIP 94903 home-value index checkpoint
Changed from $1,237,445 in September 2024 to $1,200,587 in September 2025.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94903 (not a parcel appraisal)
Other permit issued (B42310)
Recorded status: Issued
Updating two bathrooms. Like for like and no structural changes. · Declared valuation: $15,000 · Contractor: Owner
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
Other permit application filed (B42310)
Current status: Issued
Updating two bathrooms. Like for like and no structural changes. · Declared valuation: $15,000 · Contractor: Owner
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
2 Mt Wittenburg Ct (Adu 2a) · 1 unit · $125,000 valuation
Records span May 29, 2024 to Feb 11, 2025 (2 permits).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Annual ZIP 94903 home-value index checkpoint
Changed from $1,210,123 in September 2023 to $1,237,445 in September 2024.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94903 (not a parcel appraisal)
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 5.5 yr (since Apr 30, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
In "Applied" for 4.4 yr (since Jun 7, 2022), exceeding the 55d median and 261d 90th percentile for demolition permits in Unincorporated Marin (n=130).
In "Applied" for 4.8 yr (since Jan 20, 2022), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Active in "Issued" for 2.5 yr (first record May 29, 2024) with no new permit activity recorded in 21 mo.
Active in "Issued" for 8.5 yr (first record May 29, 2018) with no new permit activity recorded in 8.4 yr.
Active in "Issued" for 3.3 yr (first record Jul 19, 2023) with no new permit activity recorded in 2.5 yr.
Substantial improvements (additions, interior remodels, ADUs, commercial TI, and new builds) across 768 parcels
Small prior baseline
City baseline: 16.3 / 1k
10 in trailing 24m
Includes 3 ADUs
| Builder / contractor | Primary specialty | Here / ½ mi | ½ mi valuation | Citywide 24m trend |
|---|---|---|---|---|
| Owner | Remodel / interior alteration | 2 on parcel11 in ½ mi | $536,000 | 25 vs 15 prior+67% |
| Morris Roofing | Roof replacement | 1 on parcel1 in ½ mi | $23,660 | 0 vs 0 prior |
| I Cannan Electric | Electrical / panel | 1 on parcel1 in ½ mi | $1,500 |
| Permit category | Sample (n) | 25th pct | Median (50th) | 75th pct | 90th pct | Recent 24m median |
|---|---|---|---|---|---|---|
| New single-family home | 121 | 166d | 253d | 456d | 686d | 210d(vs 276d 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 94903
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 ($13,700/yr) + local voter-approved bond debt ($2,055/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.
−$63,857/yr
Cash needed: $301,400
NOI: $19,272/yr
P&I: $6,927/mo
For $0/mo net cash flow
At $4,175/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 | $3,841/mo | −$5,801/mo | -23.1% | $11,939/mo | −$5,769/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $4,175/mo | −$5,321/mo | -21.2% | $11,050/mo | −$5,053/mo |
| Optimistic (cap-limited) | +6% starting rent, 3% vacancy, 4.5%/yr rent growth (capped by AB 1482 ceiling of 8.6%/yr) | $4,426/mo | −$5,046/mo | -20.1% | $10,794/mo | −$4,507/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.
Service Upgrade
Updating two bathrooms. Like for like and no structural changes.
reroof — ReRoofing
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel (APN) · Retrieved Nov 14, 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 14, 2026
0.17 acres
Assessor's classification for assessment purposes. This is not zoning.
21 MT WHITNEY DR
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Nov 14, 2026
Search by parcel number 164-064-08. Assessed value is not market value.
Search by parcel number 164-064-08 (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 |
| Owner Builder Recent nearby: 36 Bridgegate Dr (Apr 11, 2025) | Remodel / interior alteration | 23 in ½ mi | $1,651,706 | 226 vs 240 prior−6% |
| Marin Kitchen Works Merged: MARIN KITCHEN WORKS · MARIN KITCHEN WORKS INC Recent nearby: 1220 Idylberry Rd (Mar 15, 2024) | Addition (adds square footage) | 5 in ½ mi | $455,000 | 0 vs 2 prior |
| Landmark Bldrs Recent nearby: 38 Oak Mountain Ct (Nov 23, 2020) | New garage / accessory structure | 5 in ½ mi | $430,500 | 0 vs 0 prior |
| Fontana Construction Recent nearby: 1605 Lucas Valley Rd (Feb 25, 2019) | Demolition | 5 in ½ mi | $135,500 | 1 vs 3 prior |
| Grant Ian Hetherington Recent nearby: 30 Maoli Dr (Jul 16, 2021) | New garage / accessory structure | 3 in ½ mi | $708,000 | 0 vs 0 prior |
| Juan Calmell Recent nearby: 20 Maoli Dr (Sep 18, 2014) | Remodel / interior alteration | 3 in ½ mi | $177,000 | 0 vs 0 prior |
| Paris Construction Service Recent nearby: 6 Mt Mc Kinley Rd (Dec 21, 2020) | Remodel / interior alteration | 3 in ½ mi | $141,550 | 0 vs 0 prior |
| 316 |
| 103d |
| 160d |
| 249d |
| 440d |
| 159d(vs 166d 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) |
| Roof replacementOn this parcel | 3,663 | 0d | 0d | 0d | 0d | 0d |
| Electrical / panelOn this parcel | 3,020 | 0d | 0d | 0d | 2d | 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.