Tiburon 94920 · APN 034-252-03 · Tiburon
Since October 2024 within ½ mile: 1 homes completed, 5 permitted, 1 proposed or in review.
7 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.
1 permits within ½ mile since October 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 Oct 30, 2026
$3,634,000
Benchmark range: $3,089,000 – $4,179,000
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 Oct 30, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the State Responsibility Area (effective 2024-04-01) (retrieved Oct 26, 2026) · CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones in the Local Responsibility Area (map dated 2025-03-24) (retrieved Oct 26, 2026) · FEMA, National Flood Hazard Layer — flood hazard zones (retrieved Oct 26, 2026) · FEMA, National Flood Hazard Layer — FIRM panels (retrieved Oct 26, 2026) · California Geological Survey, Alquist-Priolo Earthquake Fault Zones (retrieved Oct 26, 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.
In "Entitled" for 8.1 yr (since Sep 20, 2018), with no new permit record in 8.1 yr. · 1 unit
In "Entitled" for 6.9 yr (since Dec 10, 2019), with no new permit record in 6.9 yr. · 1 unit
Permit issued and active for 3.1 yr (first record Sep 7, 2023), with no completion or new permit record in 3.1 yr. · 1 unit
Permit issued and active for 2.8 yr (first record Jan 12, 2024), with no completion or new permit record in 2.8 yr. · 1 unit
Permit issued and active for 2.7 yr (first record Jan 30, 2024), with no completion or new permit record in 2.7 yr. · 1 unit
Permit issued and active for 2.5 yr (first record May 16, 2024), with no completion or new permit record in 2.5 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)
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)
Building permit reported to State HCD for 1 housing unit (ADU)
Reported in 2025 Housing Element Annual Progress Report
ADU · Owner
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: parcel
Planning entitlement approved for 1 housing unit (ADU)
Reported in 2025 Housing Element Annual Progress Report
ADU · Owner
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: parcel
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)
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)
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 18 mo (first record Apr 22, 2025) with no new permit activity recorded in 18 mo.
Active in "Issued" for 2.7 yr (first record Jan 30, 2024) with no new permit activity recorded in 2.7 yr.
Active in "Entitled" for 6.9 yr (first record Dec 10, 2019) with no new permit activity recorded in 6.9 yr.
Active in "Entitled" for 8.1 yr (first record Sep 20, 2018) with no new permit activity recorded in 8.1 yr.
Active in "Issued" for 19 mo (first record Apr 2, 2025) with no new permit activity recorded in 19 mo.
Active in "Issued" for 16 mo (first record Jun 18, 2025) with no new permit activity recorded in 16 mo.
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 ($36,350/yr) + local voter-approved bond debt ($5,453/yr) + fixed direct levies/Mello-Roos ($450/yr).
Insurance & hazard context:
−$226,718/yr
Cash needed: $799,700
NOI: -$6,152/yr
P&I: $18,381/mo
For $0/mo net cash flow
At $4,100/mo 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 | −$19,364/mo | -29.1% | $30,802/mo | −$19,503/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $4,100/mo | −$18,893/mo | -28.4% | $28,510/mo | −$18,799/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 | −$18,623/mo | -27.9% | $27,848/mo | −$18,264/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 unitsApr 22, 2025 – Apr 22, 2025
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 Oct 30, 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 |
|---|---|---|---|---|---|---|
| 2025 | ADU(ADU24-031) | ADU · Owner | 1 (Apr 22, 2025) | 1 (Apr 23, 2025) | — | — |
Source: California HCD, Housing Element Annual Progress Report — Table A2 · Geography: project (parcel) · Retrieved Oct 26, 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 Oct 30, 2026
0.32 acres
Assessor's classification for assessment purposes. This is not zoning.
23 MERCURY AVE; 23 MERCURY AVE UNIT A
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Oct 30, 2026
Search by parcel number 034-252-03. Assessed value is not market value.
Search by parcel number 034-252-03 (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.