Dillon Beach 94929 · Dillon Beach · APN 100-131-19 · Unincorporated Marin
Zoned C-R1-BD in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $1,396,000 ($1,228,000–$1,564,000).
Zoned C-R1-BD supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 4,922 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
On-parcel permit history is indexed through Feb 28, 2019, 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, 1 proposed or in review.
3 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.
127 permits within ½ mile since November 2024
$1,396,000
Benchmark range: $1,228,000 – $1,564,000
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 Apr 1, 2024)
Closest lead: New home at 40 Sea Bluff (0.15 mi 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)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,375/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 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 C-R1-BD 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 11.9 yr (first record Dec 17, 2014), with no completion or new permit record in 11.3 yr. · 1 unit · $400,000 declared valuation
Permit issued and active for 3.5 yr (first record May 16, 2023), with no completion or new permit record in 3.2 yr. · 1 unit · $1,420,000 declared valuation
Permit issued and active for 3.4 yr (first record Jun 2, 2023), with no completion or new permit record in 3.1 yr. · 1 unit · $1,600,000 declared valuation
In "Applied" for 2.5 yr (since May 13, 2024), with no new permit record in 2.5 yr. · 1 unit
Permit issued and active for 4 yr (first record Nov 29, 2022), with no completion or new permit record in 2.3 yr. · 1 unit · $1,000,000 declared valuation
Permit issued and active for 3.4 yr (first record Jun 6, 2023), with no completion or new permit record in 2.1 yr. · 1 unit · $1,783,932 declared valuation
Nearby windows / doors / siding (36 Park Ave): Description text was updated
Record 94641 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby windows / doors / siding (36 Park Ave): First appeared in published agency feed
Record 94641 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby other (49 Cliff St): First appeared in published agency feed
Record B48933 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby plumbing / water heater / sewer (30 Kameha Way): First appeared in published agency feed
Record B48925 · 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 $1,357,919 in September 2025 to $1,359,974 in September 2026.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94929 (not a parcel appraisal)
38 Kona Ln · 1 unit · $400,000 valuation
Records span Apr 5, 2022 to Sep 1, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
22 Kameha Way (Adu 22a) · 1 unit · $156,800 valuation
Records span Dec 2, 2025 to Apr 8, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Annual ZIP 94929 home-value index checkpoint
Changed from $1,349,222 in September 2024 to $1,357,919 in September 2025.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94929 (not a parcel appraisal)
14 Maui Ln · 1 unit
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
314 Oceana Dr · 1 unit · $1,783,932 valuation
Records span Jun 6, 2023 to Oct 15, 2024 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Annual ZIP 94929 home-value index checkpoint
Changed from $1,289,393 in September 2023 to $1,349,222 in September 2024.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94929 (not a parcel appraisal)
429 Oceana Dr · 1 unit · $1,000,000 valuation
Records span Nov 29, 2022 to Jul 12, 2024 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
443 Oceana Dr · 1 unit
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
40 Sea Bluff · 1 unit · $1,600,000 valuation
Records span Jun 2, 2023 to Oct 10, 2023 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Annual ZIP 94929 home-value index checkpoint
Changed from $1,397,143 in September 2022 to $1,289,393 in September 2023.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94929 (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 →Active in "Issued" for 3.4 yr (first record Jun 2, 2023) with no new permit activity recorded in 3.1 yr. High-impact scale (1 housing unit, $1,600,000 declared valuation across 1 permit).
Active in "Issued" for 3.5 yr (first record May 16, 2023) with no new permit activity recorded in 3.2 yr. High-impact scale (1 housing unit, $1,420,000 declared valuation across 1 permit).
Active in "Issued" for 3.4 yr (first record Jun 6, 2023) with no new permit activity recorded in 2.1 yr. High-impact scale (1 housing unit, $1,783,932 declared valuation across 1 permit).
Active in "Issued" for 4 yr (first record Nov 29, 2022) with no new permit activity recorded in 2.3 yr. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
In "Applied" for 2.5 yr (since May 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 11.9 yr (first record Dec 17, 2014) with no new permit activity recorded in 11.3 yr.
| Builder / contractor | Primary specialty | Here / ½ mi | ½ mi valuation | Citywide 24m trend |
|---|---|---|---|---|
| David Penny Construction Services | Windows / doors / siding | 1 on parcel1 in ½ mi | $2,000 | 0 vs 0 prior |
| Owner Builder Recent nearby: 11 North St (Aug 19, 2026) | Remodel / interior alteration | 19 in ½ mi | $6,327,932 | 226 vs 240 prior−6% |
| Owner Recent nearby: 35 Park Ave (Feb 27, 2020) | New garage / accessory structure |
| 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 94929
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 ($13,950/yr) + local voter-approved bond debt ($2,093/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.
−$76,575/yr
Cash needed: $306,900
NOI: $8,072/yr
P&I: $7,054/mo
For $0/mo net cash flow
At $3,000/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 | $2,760/mo | −$6,726/mo | -26.3% | $12,149/mo | −$6,743/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $3,000/mo | −$6,381/mo | -25.0% | $11,245/mo | −$6,229/mo |
| Optimistic (cap-limited) | +6% starting rent, 3% vacancy, 4.5%/yr rent growth (capped by AB 1482 ceiling of 8.6%/yr) | $3,180/mo | −$6,183/mo | -24.2% | $10,983/mo | −$5,837/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.
Wndw Install.***Bwop T.D. 2/27/19
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.
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 13, 2026
0.11 acres
Assessor's classification for assessment purposes. This is not zoning.
20 SUMMER ST
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Nov 13, 2026
Search by parcel number 100-131-19. Assessed value is not market value.
Search by parcel number 100-131-19 (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.
| 9 in ½ mi |
| $1,050,200 |
| 25 vs 15 prior+67% |
| Roseberry Construction Recent nearby: 82 Ocean View Ave (Jan 27, 2020) | New garage / accessory structure | 5 in ½ mi | $258,000 | 0 vs 0 prior |
| Carreiro Tom Const Recent nearby: 415 Oceana Dr (Jun 6, 2017) | New garage / accessory structure | 2 in ½ mi | $600,000 | 0 vs 0 prior |
| Js Construction Recent nearby: 25 Kailua Way (Mar 10, 2021) | New garage / accessory structure | 2 in ½ mi | $192,500 | 0 vs 0 prior |
| California Knight Recent nearby: 16 Kailua Way (Jul 5, 2023) | Remodel / interior alteration | 2 in ½ mi | $150,000 | 1 vs 2 prior |
| Fault Line Builders Recent nearby: 21 Tahiti Way (Mar 8, 2017) | Remodel / interior alteration | 2 in ½ mi | $20,050 | 0 vs 0 prior |
| Benchmark Builders Recent nearby: 438 Oceana Dr (Apr 13, 2022) | New single-family home | 1 in ½ mi | $1,100,000 | 0 vs 0 prior |
| Trinity Perfect Construction Recent nearby: 429 Oceana Dr (Jul 12, 2024) | New single-family home | 1 in ½ mi | $1,000,000 | 0 vs 0 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) |
| Windows / doors / sidingOn this parcel | 1,476 | 0d | 0d | 0d | 5d | 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.