Tiburon 94920 · APN 055-252-16 · Tiburon
Zoned R-1 in Tiburon with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $3,734,000 ($3,174,000–$4,294,000).
Zoned R-1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 20,125 sq ft lot.
Source: Tiburon zoning · CA Gov. Code 66314 & 65852.21
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 (380 ft S, 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)
Automated synthesis of indexed municipal, county, state, and federal public records — informational context only, not a formal appraisal, survey, or legal/tax determination.
Since — within ½ mile: 2 permitted, 2 proposed or in review.
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.
No permit activity recorded within ½ mile.
$3,734,000
Benchmark range: $3,174,000 – $4,294,000
Permit counts and nearby activity on this page may omit municipal counter records. Request a parcel permit report directly from the local building department.
Source: Source coverage registry (Tiburon)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$3,616/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector
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.
We don't have building permits for Tiburon, so we can't show what has been permitted nearby.
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 Tiburon'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 R-1 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 22, 2018), with no completion or new permit record in 8.5 yr. · 1 unit
Permit issued and active for 8.2 yr (first record Aug 30, 2018), with no completion or new permit record in 8.2 yr. · 1 unit
Permit issued and active for 7.4 yr (first record Jun 18, 2019), with no completion or new permit record in 7.4 yr. · 1 unit
Permit issued and active for 3.6 yr (first record Apr 18, 2023), with no completion or new permit record in 3.6 yr. · 1 unit
Permit issued and active for 3.5 yr (first record May 3, 2023), with no completion or new permit record in 3.5 yr. · 1 unit
In "Entitled" for 3.4 yr (since Jun 22, 2023), with no new permit record in 3.4 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)
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 housing unit completed (ADU22-004)
Reported in 2024 Housing Element Annual Progress Report
ADU · Renter
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: parcel
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)
1 unit
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
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 $3,353,968 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)
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 Tiburon development graph →Active in "Issued" for 8.5 yr (first record May 22, 2018) with no new permit activity recorded in 8.5 yr.
Active in "Issued" for 7.4 yr (first record Jun 18, 2019) with no new permit activity recorded in 7.4 yr.
Active in "Issued" for 2.2 yr (first record Sep 10, 2024) with no new permit activity recorded in 2.2 yr.
Active in "Issued" for 23 mo (first record Dec 17, 2024) with no new permit activity recorded in 23 mo.
Active in "Issued" for 8.2 yr (first record Aug 30, 2018) with no new permit activity recorded in 8.2 yr.
Active in "Issued" for 2.4 yr (first record Jun 3, 2024) with no new permit activity recorded in 2.4 yr.
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 ($37,350/yr) + local voter-approved bond debt ($5,603/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.
−$233,936/yr
Cash needed: $821,700
NOI: -$7,302/yr
P&I: $18,886/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 | −$19,966/mo | -29.2% | $31,642/mo | −$20,112/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $4,100/mo | −$19,495/mo | -28.5% | $29,287/mo | −$19,409/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 | −$19,224/mo | -28.1% | $28,607/mo | −$18,873/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.
Finaled / completed1 unitsApr 5, 2022 – Apr 5, 2022
We group related permits and State housing reports into projects. That grouping is our inference, not an official record.
No building permits are recorded for this parcel since 2016.
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.
| Report year | Project / record | Type | Entitled | Permitted | Completed | Deed-restricted |
|---|---|---|---|---|---|---|
| 2024 | —(ADU22-004) | ADU · Renter | 1 (Apr 20, 2022) | 1 (Apr 5, 2022) | 1 (Oct 22, 2024) | — |
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: project (parcel) · Retrieved Nov 9, 2026 · From Tiburon'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
0.46 acres
Assessor's classification for assessment purposes. This is not zoning.
840A STONY HILL RD; 840B STONY HILL RD; 840 STONY HILL RD
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Nov 14, 2026
Search by parcel number 055-252-16. Assessed value is not market value.
Search by parcel number 055-252-16 (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.