$4,999,000
3343 Alpine Rd, Portola Valley 94028
AddressIntel AI Briefing
The optimal play is teardown-and-mansionize to redesign a modern landmark on this sprawling four-acre hillside parcel. Developing at this scale will attract high-end buyers seeking ultimate privacy and custom estate amenities.
Property Permit History
Recent Neighborhood Remodeling (Portola Valley)
Parcel & Zoning Info
ADU Potential
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.
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
Henry M. Gunn 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
50/100
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.
Median of 4 recent single-family sales in Portola Valley (94028): $3,452/sqft, plus 5% because new houses sold at a median 1.07x their comps across 239 real rebuilds. Sized within 25% of the 10,200 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 10,200 sqft build: sales within 25% of it. Smaller houses sell for more per foot, so pricing a rebuild off them overstates resale.