Tiburon 94920 · Paradise Cay · APN 038-122-23 · Unincorporated Marin
Zoned RSP-5.8-BFC in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (local responsibility area) due diligence; benchmark value $3,114,000 ($2,740,000–$3,488,000).
Zoned RSP-5.8-BFC supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 10,367 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
On-parcel permit history is indexed through Aug 28, 2023, 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: 1 permitted.
1 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.
94 permits within ½ mile since November 2024
$3,114,000
Benchmark range: $2,740,000 – $3,488,000
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: New home at 149 Jamaica St (0.1 mi E, issued). 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 (~$3,022/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.
No ADU or new-home permits recorded within ¼ mile in this window.
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 RSP-5.8-BFC 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 12.8 yr (first record Feb 12, 2014), with no completion or new permit record in 12.3 yr. · 1 unit · $400,000 declared valuation
Permit issued and active for 12.8 yr (first record Feb 12, 2014), with no completion or new permit record in 12.3 yr. · 1 unit · $425,000 declared valuation
Permit issued and active for 12.8 yr (first record Feb 12, 2014), with no completion or new permit record in 12.3 yr. · 1 unit · $450,000 declared valuation
Permit issued and active for 12.8 yr (first record Feb 12, 2014), with no completion or new permit record in 12.3 yr. · 1 unit · $480,000 declared valuation
Permit issued and active for 12.8 yr (first record Feb 12, 2014), with no completion or new permit record in 12.3 yr. · 1 unit · $400,000 declared valuation
Permit issued and active for 12.2 yr (first record Aug 19, 2014), with no completion or new permit record in 12 yr. · 1 unit · $750,000 declared valuation
Nearby windows / doors / siding (4660 Paradise Dr): First appeared in published agency feed
Record B48974 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (284 Trinidad Dr): First appeared in published agency feed
Record B48956 · 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 $3,090,631 in September 2025 to $3,404,730 in September 2026.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94920 (not a parcel appraisal)
Annual ZIP 94920 home-value index checkpoint
Changed from $3,209,701 in September 2024 to $3,090,631 in September 2025.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94920 (not a parcel appraisal)
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Annual ZIP 94920 home-value index checkpoint
Changed from $3,258,065 in September 2023 to $3,209,701 in September 2024.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94920 (not a parcel appraisal)
Annual ZIP 94920 home-value index checkpoint
Changed from $3,353,968 in September 2022 to $3,258,065 in September 2023.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94920 (not a parcel appraisal)
Plumbing / water heater / sewer permit application filed (B35202)
Current status: Issued
Replace old water heater same location with new — Replace Plumbing Fixtures(s) · Declared valuation: $4,500 · Contractor: Reggie'S Reliable Plumbing Service Inc
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
Plumbing / water heater / sewer permit issued (B35202)
Recorded status: Issued
Replace old water heater same location with new — Replace Plumbing Fixtures(s) · Declared valuation: $4,500 · Contractor: Reggie'S Reliable Plumbing Service Inc
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
Annual ZIP 94920 home-value index checkpoint
Changed from $3,038,417 in September 2021 to $3,353,968 in September 2022.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94920 (not a parcel appraisal)
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
1 unit
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
1 unit
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Annual ZIP 94920 home-value index checkpoint
Changed from $2,509,451 in September 2020 to $3,038,417 in September 2021.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94920 (not a parcel appraisal)
1 unit
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 12.2 yr (first record Aug 19, 2014) with no new permit activity recorded in 12 yr. High-impact scale (1 housing unit, $750,000 declared valuation across 1 permit).
Active in "Issued" for 11.4 yr (first record Jun 2, 2015) with no new permit activity recorded in 11.2 yr. High-impact scale (1 housing unit, $1,200,000 declared valuation across 1 permit).
In "Entitled" for 5.1 yr (since Oct 7, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
In "Entitled" for 8.5 yr (since May 17, 2018), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Active in "Issued" for 5.8 yr (first record Jan 21, 2021) with no new permit activity recorded in 5.8 yr.
Active in "Issued" for 12.8 yr (first record Feb 12, 2014) with no new permit activity recorded in 12.3 yr.
Substantial improvements (additions, interior remodels, ADUs, commercial TI, and new builds) across 294 parcels
Small prior baseline
City baseline: 16.3 / 1k
4 in trailing 24m
Includes 0 ADUs
| Builder / contractor | Primary specialty | Here / ½ mi | ½ mi valuation | Citywide 24m trend |
|---|---|---|---|---|
| Reggies Reliable Plumbing Service | Plumbing / water heater / sewer | 1 on parcel1 in ½ mi | $4,500 | 0 vs 0 prior |
| Owner Builder Recent nearby: 114 St Thomas Way (Sep 30, 2024) | Remodel / interior alteration | 15 in ½ mi | $1,972,950 | 226 vs 240 prior−6% |
| Owner Recent nearby: 95 St Thomas Way (May 24, 2021) | Remodel / interior alteration |
| 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 94920
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 ($31,150/yr) + local voter-approved bond debt ($4,673/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.
−$190,505/yr
Cash needed: $685,300
NOI: -$1,492/yr
P&I: $15,751/mo
For $0/mo net cash flow
At $4,100/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 | $3,772/mo | −$16,347/mo | -28.6% | $26,590/mo | −$16,455/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $4,100/mo | −$15,875/mo | -27.8% | $24,611/mo | −$15,752/mo |
| Optimistic (cap-limited) | +6% starting rent, 3% vacancy, 4.5%/yr rent growth (capped by AB 1482 ceiling of 8.6%/yr) | $4,346/mo | −$15,605/mo | -27.3% | $24,039/mo | −$15,217/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.
Replace old water heater same location with new — Replace Plumbing Fixtures(s)
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
0.24 acres
Assessor's classification for assessment purposes. This is not zoning.
23 ANTILLES WAY
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Nov 14, 2026
Search by parcel number 038-122-23. Assessed value is not market value.
Search by parcel number 038-122-23 (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.
| 11 in ½ mi |
| $1,246,160 |
| 25 vs 15 prior+67% |
| Davidson Builders Recent nearby: 272 Trinidad Dr - Lot 28 (Apr 6, 2016) | New single-family home | 9 in ½ mi | $3,478,800 | 0 vs 0 prior |
| Lamperti Contracting And Design Recent nearby: 269 Trinidad Dr (Dec 14, 2023) | Remodel / interior alteration | 4 in ½ mi | $571,718 | 2 vs 7 prior |
| Singlepoint Design Build Recent nearby: 87 St Thomas Way (Feb 19, 2015) | Addition (adds square footage) | 2 in ½ mi | $1,500,000 | 2 vs 0 prior |
| Royoco Construction And Development Recent nearby: 127 St Thomas Way (Oct 3, 2019) | Addition (adds square footage) | 2 in ½ mi | $458,000 | 0 vs 0 prior |
| Alliance Custom Builders Recent nearby: 228 Martinique Ave (May 20, 2024) | Remodel / interior alteration | 2 in ½ mi | $371,000 | 0 vs 2 prior |
| Marinkitchenco Recent nearby: 9 Saba Ln (Jun 26, 2020) | Remodel / interior alteration | 2 in ½ mi | $136,668 | 0 vs 1 prior |
| All Phase Construction Recent nearby: 8 St Lucia Pl (Nov 20, 2014) | Remodel / interior alteration | 2 in ½ mi | $110,000 | 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) |
| Plumbing / water heater / sewerOn this parcel | 2,211 | 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.