$2,975,000
145 43rd Ave, San Mateo 94403
AddressIntel AI Briefing
Already built out to its max 40% FAR, the existing remodeled house offers zero expansion potential. The best play is stealth density: primary + ADU + JADU to squeeze rental yield out of the remaining lot space. A steep entry price relative to size-matched resale rates kills any standard flip scenario.
Property Permit History
Recent Neighborhood Remodeling (San Mateo)
Parcel & Zoning Info
ADU Potential
Flag / irregular · Corner lot · ~108 ft frontage × 118 ft deep, a tucked-away rear unit is very private; access is typically via the pole driveway. 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
Existing home already uses most of the allowable floor area, little expansion headroom. Zoning allows roughly 3,022 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
Laurel 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
85/100
Based on recent sales velocity and local demand in 94403.
Flippability Score
15/100
Measures neighborhood renovation density vs. recent permits on this property.
Bidding War Prob.
66%
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 3,022 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 San Mateo (94403): $1,073/sqft. Sized within 25% of the 3,000 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.
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: Project is mathematically underwater.
Recent Comparables (San Mateo 94403)
Sized to the modelled 3,000 sqft build: sales within 25% of it. Smaller houses sell for more per foot, so pricing a rebuild off them overstates resale.