Tiburon 94920 · Unincorporated Tiburon · APN 059-201-18 · Unincorporated Marin
Zoned R1 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 $3,151,000 ($2,773,000–$3,529,000).
Zoned R1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 10,934 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
Public building records show issued construction/renovation work on this parcel (1 total permit, latest May 15, 2019).
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: 8 permitted, 1 proposed or in review.
9 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.
28 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.
$3,151,000
Benchmark range: $2,773,000 – $3,529,000
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)
New home at 2448 Spanish Trl Rd Aka: Active in "Issued" for 8.2 yr (first record Sep 18, 2018) with no new permit activity recorded in 7.5 yr.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
Closest lead: New home (0.41 mi SW, 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)
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 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 8.2 yr (first record Sep 18, 2018), with no completion or new permit record in 7.5 yr. · 1 unit · $46,000 declared valuation
Permit issued and active for 8.1 yr (first record Oct 18, 2018), with no completion or new permit record in 8.1 yr. · 1 unit
Permit issued and active for 7.3 yr (first record Jul 15, 2019), with no completion or new permit record in 7.3 yr. · 1 unit
Permit issued and active for 6 yr (first record Nov 16, 2020), with no completion or new permit record in 5.6 yr. · 1 unit · $214,000 declared valuation
Permit issued and active for 5.5 yr (first record Apr 29, 2021), with no completion or new permit record in 5.5 yr. · 1 unit
Permit issued and active for 3.7 yr (first record Mar 7, 2023), with no completion or new permit record in 3.7 yr. · 1 unit
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)
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 $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)
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)
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)
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)
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 $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)
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)
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 8.2 yr (first record Sep 18, 2018) with no new permit activity recorded in 7.5 yr.
In "Entitled" for 2.2 yr (since Aug 13, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
In "Entitled" for 2.2 yr (since Aug 13, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Active in "Issued" for 6 yr (first record Nov 16, 2020) with no new permit activity recorded in 5.6 yr.
Active in "Issued" for 2 yr (first record Oct 28, 2024) with no new permit activity recorded in 2 yr.
Active in "Issued" for 22 mo (first record Jan 14, 2025) with no new permit activity recorded in 22 mo.
| Builder / contractor | Primary specialty | Here / ½ mi | ½ mi valuation | Citywide 24m trend |
|---|---|---|---|---|
| Owner Builder | Accessory dwelling unit (new or conversion) | 1 on parcel8 in ½ mi | $2,085,000 | 226 vs 240 prior−6% |
| Owner Recent nearby: 2641 Paradise Dr (Jul 10, 2019) | Addition (adds square footage) | 2 in ½ mi | $475,000 | 25 vs 15 prior+67% |
| Sausalito Construction Recent nearby: 2400 Mar East St (Feb 7, 2017) |
| 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 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 ($31,500/yr) + local voter-approved bond debt ($4,725/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.
−$193,032/yr
Cash needed: $693,000
NOI: -$1,894/yr
P&I: $15,928/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 | −$16,557/mo | -28.7% | $26,884/mo | −$16,669/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $4,100/mo | −$16,086/mo | -27.9% | $24,883/mo | −$15,965/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 | −$15,816/mo | -27.4% | $24,305/mo | −$15,430/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.
Issued1 unitsSep 18, 2018 – May 15, 2019
We group related permits and State housing reports into projects. That grouping is our inference, not an official record.
Adu T.D. 11/1/18
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.
| Report year | Project / record | Type | Entitled | Permitted | Completed | Deed-restricted |
|---|---|---|---|---|---|---|
| 2019 | —(161535) | ADU · Renter | — | 1 (May 15, 2019) | — | — |
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
0.25 acres
Assessor's classification for assessment purposes. This is not zoning.
2448 SPANISH TRAIL RD; 2450 SPANISH TRAIL RD
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Nov 13, 2026
Search by parcel number 059-201-18. Assessed value is not market value.
Search by parcel number 059-201-18 (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.
| Remodel / interior alteration |
| 2 in ½ mi |
| $281,000 |
| 0 vs 0 prior |
| Deetken Construction Recent nearby: 2402 Vista Del Mar Ln (Oct 19, 2015) | Remodel / interior alteration | 2 in ½ mi | $255,000 | 0 vs 0 prior |
| Wojak Construction Recent nearby: 2370 Vista Del Mar Ln (Sep 22, 2014) | Remodel / interior alteration | 2 in ½ mi | $80,000 | 0 vs 0 prior |
| Floyd Construction Recent nearby: 2495 Paradise Dr (Mar 30, 2015) | New single-family home | 1 in ½ mi | $1,100,000 | 3 vs 5 prior |
| William G Taylor Construction Recent nearby: 2475 Mar East St (Apr 25, 2018) | New garage / accessory structure | 1 in ½ mi | $500,000 | 0 vs 0 prior |
| Danny Gallagher Construction Recent nearby: 2400 Paradise Dr (Dec 5, 2025) | Addition (adds square footage) | 1 in ½ mi | $250,000 | 1 vs 2 prior |
| Lighthouse Const Service Recent nearby: 2457 Mar East St (Jan 6, 2021) | Remodel / interior alteration | 1 in ½ mi | $225,000 | 0 vs 0 prior |
| Kelly Domer Partners Dba Pacific Constr Recent nearby: 2483 Mar East St (Nov 6, 2014) | Remodel / interior alteration | 1 in ½ mi | $185,000 | 4 vs 2 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) |
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.