$9,850,000
333 Walsh Rd, Atherton 94027
AddressIntel AI Briefing
This massive 1.4-acre lot in ultra-exclusive Atherton presents a prime opportunity for a teardown-and-mansionize play. The existing century-old structure has exceptionally low lot coverage, and with zero hazard zones and elite local demographics, it is the perfect canvas for a premier custom estate. Strong regional permit activity for multi-million dollar builds underscores the high demand for new construction in this tier.
Property Permit History
Recent Neighborhood Remodeling (Atherton)
Parcel & Zoning Info
ADU Potential
Flag / irregular · ~340 ft frontage × 356 ft deep, a tucked-away rear unit is very private; access is typically via the pole driveway.
Screening heuristic based on lot size, existing coverage, lot orientation, and hazard overlays. CA ADU law is ministerial statewide; verify max size, setbacks, and JADU owner-occupancy with the local planning dept.
Redevelopment Potential
Small, older home using a low share of the allowable building envelope on a sizable lot, a scrape-and-rebuild or major-expansion play. Zoning allows roughly 11,280 sqft of gross floor area on this lot.
Screening estimate comparing existing living area to the city's single-family floor-area limit. FAR rule curated from current municipal code. Source: Atherton Muni Code 17.32.040 (R-1A), district from Town zoning GIS (as of 2026-08-24). Verify FAR, coverage, setbacks, and height with the local planning dept.
Hazard Snapshot
Flood Zone
Fire Severity
Liquefaction
Fault Zone
Not a substitute for a Natural Hazard Disclosure (NHD) report. Zones reflect available GIS data and may not cover all localities.
Nearby Public Schools
Las Lomitas Elementary
Las Lomitas Elementary
La Entrada Middle
Las Lomitas Elementary
Woodside High
Sequoia Union High
School boundaries are subject to change. Nearest school distance does not guarantee enrollment eligibility. Check with the local district. Data provided by CDE.
Proprietary Intelligence
Market Heat Index
58/100
Based on recent sales velocity and local demand in 94027.
Flippability Score
88/100
Measures neighborhood renovation density vs. recent permits on this property.
Bidding War Prob.
33%
Likelihood of multiple offers based on local list-to-sale ratios and DOM.
Proforma ROI Calculator
Back-of-the-napkin deal analysis across development strategies.
Zoning allows roughly 11,280 sqft on this lot, and the default builds to that envelope. The FAR figure is a discretionary-review trigger, not a hard cap.
Median of 12 recent single-family sales in Atherton (94027): $2,247/sqft. Sized within 25% of the 11,300 sqft build, because smaller houses sell for more per foot and pricing a rebuild off them overstates resale.
Commission, transfer tax and closing. Deducted from resale before profit, so the ROI below is net of the exit rather than gross.
Carry on total capital for the project duration. At 0% the model is a cash purchase; 12 months at a typical construction-loan rate moves ROI by 6 to 10 points on a deal this size, so price it with your real rate.
Projected Profit
Recent Comparables (Atherton 94027)
Sized to the modelled 11,300 sqft build: sales within 25% of it. Smaller houses sell for more per foot, so pricing a rebuild off them overstates resale.