$9,888,070
27 Valley Rd, Atherton 94027
AddressIntel AI Briefing
The optimal play is teardown-and-mansionize to build an 18,040 sqft luxury estate. Liquefaction acts as a structural blocker requiring specialized geotechnical engineering, but high median household income and massive resale values support the added costs.
Property Permit History
Recent Neighborhood Remodeling (Atherton)
Parcel & Zoning Info
ADU Potential
Flag / irregular · ~279 ft frontage × 286 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
Meaningful unused floor-area headroom under current zoning, room to add square footage. Zoning allows roughly 8,118 sqft of gross floor area on this lot.
Screening estimate comparing existing living area to the city's single-family floor-area limit. FAR figure is a discretionary-review trigger, not a hard cap. Treat as approximate. Source: Atherton Muni Code 17.32.040 (R-1A); 17.33.040 (R-1B) (as of 2026-08-18). 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
57/100
Based on recent sales velocity and local demand in 94027.
Flippability Score
70/100
Measures neighborhood renovation density vs. recent permits on this property.
Bidding War Prob.
29%
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 8,118 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): $2,116/sqft. Sized within 25% of the 8,100 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
Warning: Margin is tight for the construction risk.
Recent Comparables (Atherton 94027)
Sized to the modelled 8,100 sqft build: sales within 25% of it. Smaller houses sell for more per foot, so pricing a rebuild off them overstates resale.