Mill Valley 94941 · Strawberry · APN 043-122-18 · Unincorporated Marin
Zoned RSP-5 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,316,000 ($2,038,000–$2,594,000).
Zoned RSP-5 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 15,420 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
Public building records show issued construction/renovation work on this parcel (9 total permits, latest Dec 17, 2025).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
43 substantial renovation & housing permits over 24 months (28.4 per 1,000 parcels vs. 16.4 citywide baseline) (#1 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Strawberry)
Automated synthesis of indexed municipal, county, state, and federal public records — informational context only, not a formal appraisal, survey, or legal/tax determination.
$2,316,000
Benchmark range: $2,038,000 – $2,594,000
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)
Plumbing / water heater / sewer (168685): Issued after 2 mo — slower than 90% of plumbing / water heater / sewer permits in Unincorporated Marin (median 0d, 90th pct 0d, n=2,211).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
Closest lead: New home (410 ft N, 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)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,257/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector
Since November 2024 within ½ mile: 4 permitted, 1 proposed or in review; 2 demolitions.
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.
125 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.
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 RSP-5 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 12.9 yr (first record Dec 30, 2013), with no completion or new permit record in 12.6 yr. · 1 unit · $700,000 declared valuation
Permit issued and active for 12.9 yr (first record Dec 11, 2013), with no completion or new permit record in 12.3 yr. · 1 unit · $600,000 declared valuation
Permit issued and active for 12 yr (first record Nov 5, 2014), with no completion or new permit record in 12 yr. · $10,000 declared valuation
Permit issued and active for 11.7 yr (first record Mar 19, 2015), with no completion or new permit record in 10.9 yr. · 1 unit · $170,000 declared valuation
Permit issued and active for 9.6 yr (first record Apr 13, 2017), with no completion or new permit record in 9.5 yr. · $55,000 declared valuation
Permit issued and active for 8.1 yr (first record Sep 19, 2018), with no completion or new permit record in 7.9 yr. · 1 unit · $30,000 declared valuation
Nearby remodel / interior alteration (144 Mission Dr): Contractor changed from (blank) to BOLT DOWN THE BAY AREA
Record 182696 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby addition (adds square footage) (6 Yellow Ferry Dock): First appeared in published agency feed
Record 94628 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby remodel / interior alteration (427 E Strawberry Dr): First appeared in published agency feed
Record 182860 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby remodel / interior alteration (427 E Strawberry Dr): No longer present in latest agency feed
Record 94356 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby plumbing / water heater / sewer (68 Seminary Cove Dr): First appeared in published agency feed
Record B48955 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
Nearby windows / doors / siding (145 Great Circle Dr): First appeared in published agency feed
Record B48901 · Detected between snapshots
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Snapshot diff within ½ mile
427 E Strawberry Dr · 1 unit · $225,000 valuation
Records span Jun 18, 2026 to Oct 20, 2026 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Latest published Zillow Home Value Index (ZHVI) update
Changed from $1,980,059 in September 2025 to $2,181,389 in September 2026.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94941 (not a parcel appraisal)
431 E Strawberry Dr · 1 unit · $400,000 valuation
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
201 Seminary Dr · $125,000 valuation
Records span Aug 22, 2025 to Jan 28, 2026 (2 permits).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Plumbing / water heater / sewer permit application filed (B45210)
Current status: Issued
Minor bathroom improvements consisting of like-for-like replacement of existing finishes and fixtures. Work includes removal and replacement of existing floor tile and wall tile within the walk-in shower, replacement of existing vanity and plumbing fixtures, toilet, and existing light fixture. No changes to the existing bathroom layout, dimensions, or use. No new fixtures, plumbing locations, or electrical locations are being added. Bathroom dimensions: approximately 11’ x 6’. Plumbing work to include upgrading existing plumbing connections to meet current code requirements. Electrical work is limited to like-for-like replacement of existing fixtures, with no modifications to circuits or locations. · Declared valuation: $19,800 · Contractor: Home Team Services Remodeling
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
Plumbing / water heater / sewer permit issued (B45210)
Recorded status: Issued
Minor bathroom improvements consisting of like-for-like replacement of existing finishes and fixtures. Work includes removal and replacement of existing floor tile and wall tile within the walk-in shower, replacement of existing vanity and plumbing fixtures, toilet, and existing light fixture. No changes to the existing bathroom layout, dimensions, or use. No new fixtures, plumbing locations, or electrical locations are being added. Bathroom dimensions: approximately 11’ x 6’. Plumbing work to include upgrading existing plumbing connections to meet current code requirements. Electrical work is limited to like-for-like replacement of existing fixtures, with no modifications to circuits or locations. · Declared valuation: $19,800 · Contractor: Home Team Services Remodeling
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · Geography: parcel
4 Heron Dr · 1 unit · $225,000 valuation
Records span Sep 2, 2025 to Dec 3, 2025 (1 permit).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
2 Nina Ct · 1 unit · $56,460 valuation
Records span Dec 9, 2022 to Oct 24, 2025 (2 permits).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) & HCD APR (grouped project within ½ mile)
Annual ZIP 94941 home-value index checkpoint
Changed from $2,042,452 in September 2024 to $1,980,059 in September 2025.
Source: Zillow Home Value Index (ZHVI) · Data provided by Zillow · Geography: ZIP 94941 (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 →Issued after 2 mo — slower than 90% of plumbing / water heater / sewer permits in Unincorporated Marin (median 0d, 90th pct 0d, n=2,211).
Pending in review for 7.3 yr (16.3× the 164d median) — slower than 90% of new garage / accessory structure permits in Unincorporated Marin (median 164d, 90th pct 485d, n=356).
In "Entitled" for 5.1 yr (since Sep 30, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
In "Applied" for 15 mo (since Aug 14, 2025), exceeding the 55d median and 261d 90th percentile for demolition permits in Unincorporated Marin (n=130).
Active in "Issued" for 21 mo (first record Feb 18, 2025) with no new permit activity recorded in 17 mo.
Active in "Issued" for 6.6 yr (first record Apr 1, 2020) with no new permit activity recorded in 6.5 yr.
Substantial improvements (additions, interior remodels, ADUs, commercial TI, and new builds) across 1,512 parcels
+52.9% YoY
City baseline: 16.4 / 1k
43 in trailing 24m
Includes 8 ADUs
| Builder / contractor | Primary specialty | Here / ½ mi | ½ mi valuation | Citywide 24m trend |
|---|---|---|---|---|
| Dan Young Construction | Remodel / interior alteration | 1 on parcel1 in ½ mi | $85,000 | 0 vs 0 prior |
| Home Team Services Remodeling | Plumbing / water heater / sewer | 1 on parcel1 in ½ mi | $19,800 | 0 vs 0 prior |
| Bellows Plumbing Heating And Air | HVAC / heat pump | 1 on parcel1 in ½ mi | $15,000 |
| 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) |
| New garage / accessory structureOn this parcel | 356 | 104d | 164d | 294d | 485d | 159d(vs 205d prior) |
HUD Small Area Fair Market Rent · ZIP 94941
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 ($23,150/yr) + local voter-approved bond debt ($3,473/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.
−$132,836/yr
Cash needed: $509,300
NOI: $7,635/yr
P&I: $11,706/mo
For $0/mo net cash flow
At $3,950/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 | $3,634/mo | −$11,524/mo | -27.2% | $19,719/mo | −$11,564/mo |
| Base (your inputs) | Your entered assumptions, 3.0%/yr rent growth | $3,950/mo | −$11,070/mo | -26.1% | $18,252/mo | −$10,886/mo |
| Optimistic (cap-limited) | +6% starting rent, 3% vacancy, 4.5%/yr rent growth (capped by AB 1482 ceiling of 8.6%/yr) | $4,187/mo | −$10,809/mo | -25.5% | $17,828/mo | −$10,370/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.
Minor bathroom improvements consisting of like-for-like replacement of existing finishes and fixtures. Work includes removal and replacement of existing floor tile and wall tile within the walk-in shower, replacement of existing vanity and plumbing fixtures, toilet, and existing light fixture. No changes to the existing bathroom layout, dimensions, or use. No new fixtures, plumbing locations, or electrical locations are being added. Bathroom dimensions: approximately 11’ x 6’. Plumbing work to include upgrading existing plumbing connections to meet current code requirements. Electrical work is limited to like-for-like replacement of existing fixtures, with no modifications to circuits or locations.
Repl & Expand 2-Level Decks; Fire Pit, Heaters
Upgrade electric meter panel to 400-amp/ 320-amp actual — Service Upgrade
Generator
Replacing top story furnace with new high efficiency unit in same location in attic, adding AC to existing top story system. Adding new AC to existing down stairs system. — Mechanical Appliance, Replace Mechanical Appliance
Trellis, Decks Outdoor Kitch
replace 2 patio sliders — Non-structural Door/Window Replacement
Kitchen & Bath Remodel T.D.2/10/16
Rplc Furnace
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
0.35 acres
Assessor's classification for assessment purposes. This is not zoning.
42 TOPSIDE WAY
Source: County of Marin GIS (MarinMap), Parcels · Geography: parcel · Retrieved Nov 13, 2026
Search by parcel number 043-122-18. Assessed value is not market value.
Search by parcel number 043-122-18 (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.
| 0 vs 0 prior |
| Golden Gate Home Improvement | Windows / doors / siding | 1 on parcel1 in ½ mi | $10,838 | 0 vs 0 prior |
| King Electric | Electrical / panel | 1 on parcel1 in ½ mi | $7,160 | 0 vs 0 prior |
| Downing Heating And Air | HVAC / heat pump | 1 on parcel1 in ½ mi | $3,920 | 0 vs 0 prior |
| Lek Enterprises Recent nearby: 2 Harbor Point Dr (Mar 6, 2023) | Remodel / interior alteration | 35 in ½ mi | $1,113,400 | 0 vs 11 prior−100% |
| Owner Builder Recent nearby: 171 Great Circle Dr (Sep 12, 2025) | Remodel / interior alteration | 33 in ½ mi | $4,891,400 | 226 vs 240 prior−6% |
| Owner Recent nearby: 425 E Strawberry Dr (Feb 3, 2020) | Remodel / interior alteration | 14 in ½ mi | $725,850 | 25 vs 15 prior+67% |
| Kerr Construction Recent nearby: 427 E Strawberry Dr (Nov 2, 2026) | New garage / accessory structure | 6 in ½ mi | $888,600 | 2 vs 2 prior |
| Accessory dwelling unit (new or conversion) | 298 | 120d | 204d | 331d | 549d | 214d(vs 181d prior) |
| Addition (adds square footage) | 316 | 103d | 160d | 249d | 440d | 157d(vs 167d prior) |
| Remodel / interior alterationOn this parcel | 1,054 | 36d | 83d | 148d | 266d | 112d(vs 77d prior) |
| Commercial tenant improvement | 81 | 99d | 148d | 233d | 443d | 152d(vs 150d prior) |
| HVAC / heat pumpOn this parcel | 2,946 | 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.