$7,495,000
1 Redberry Rdg, Portola Valley 94028
AddressIntel AI Briefing
The optimal play is teardown-and-mansionize to establish a modernized high-end estate that matches the scale of newer neighborhood landmarks. This plan makes the best use of the vast lot acreage while ensuring maximum design flexibility.
Property Permit History
Recent Neighborhood Remodeling (Portola Valley)
Parcel & Zoning Info
ADU Potential
Flag / irregular · ~308 ft frontage × 364 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.
Seller Motivation
Inferred from days on market and listing-description language (e.g. "as-is", "estate sale", "motivated seller"). A screening heuristic for likely negotiability, not a statement about the seller's circumstances.
Redevelopment Potential
Meaningful unused floor-area headroom under current zoning, room to add square footage. Zoning allows roughly 22,599 sqft of gross floor area on this lot.
Screening estimate comparing existing living area to the city's single-family floor-area limit. City sets no explicit FAR (or is not individually curated); allowable area is a conservative estimate. Source: conservative default (0.40 FAR — city not individually curated) (as of 2026-06-30). 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. Liquefaction and fault flags: modified from California Geological Survey, Web Service of Official Maps of Alquist-Priolo Earthquake Fault Zones and Web Service of Official Maps of Seismic Hazard Zones (2025).
Nearby Public Schools
Ormondale Elementary
Portola Valley Elementary
Corte Madera
Portola Valley Elementary
Palo Alto Middle College High
Palo Alto Unified
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
11/100
Based on recent sales velocity and local demand in 94028.
Flippability Score
55/100
Measures neighborhood renovation density vs. recent permits on this property.
Bidding War Prob.
1%
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.
We don't hold this jurisdiction's floor-area rule, so the default builds to roughly 22,599 sqft from a conservative 0.40 FAR approximation, a starting point and not a zoning answer. Check the local code before you rely on it.
Median of 3 recent single-family sales in Portola Valley (94028): $4,551/sqft, plus 5% because new houses sold at a median 1.07x their comps across 239 real rebuilds. Sized within 25% of the 15,000 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.
Interest on the purchase price for the whole project plus half the build budget, since construction draws ramp up. The default is 7% over 33 months, the median purchase-to-sale time of 239 real Peninsula and South Bay rebuilds. Set the rate to 0 for a cash purchase, or use your own lender's terms.
Projected Profit
Recent Comparables (Portola Valley 94028)
Sized to the modelled 15,000 sqft build: sales within 25% of it. Smaller houses sell for more per foot, so pricing a rebuild off them overstates resale.