$1,498,000
3801 Orinda Dr, San Mateo 94403
AddressIntel AI Briefing
The optimal play is a teardown-and-mansionize or an SB 9 lot split of the 78-year-old, 1,000 square foot cottage on a 5,323 square foot lot. Excellent ADU feasibility at 91/100 provides a strong alternative density play to capitalize on the $250k+ median income demographics. Liquefaction is present but represents a minor engineering hurdle rather than a blocker.
Property Permit History
Recent Neighborhood Remodeling (San Mateo)
Parcel & Zoning Info
ADU Potential
Standard lot · Corner lot · ~78 ft frontage × 99 ft deep — typical proportions for a detached ADU behind or beside the home. A second street frontage lets an ADU take its own entrance and address.
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 2,661 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: San Mateo Muni Code 27.18.060 (R1-B/C); 6,000 sqft cap (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.
Nearby Public Schools
George Hall Elementary
San Mateo-Foster City
Abbott Middle
San Mateo-Foster City
Hillsdale High
San Mateo 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
82/100
Based on recent sales velocity and local demand in 94403.
Flippability Score
78/100
Measures neighborhood renovation density vs. recent permits on this property.
Bidding War Prob.
60%
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.
Based on 6 recent sales in 94403 averaging $945/sqft.
Projected Profit
Warning: Project is mathematically underwater.