$885,000
20 Maple Ave, South San Francisco 94080
AddressIntel AI Briefing
The tight lot dimensions block any physical expansion or external ADU additions, limiting the property to its existing footprint. The optimal play is a high-end cosmetic remodel to appeal to turn-key buyers in the entry-level market. This targeted execution avoids high construction costs while delivering a polished product.
Property Permit History
Recent Neighborhood Remodeling (South San Francisco)
Parcel & Zoning Info
ADU Potential
Flag / irregular · Corner lot · ~49 ft frontage × 76 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.
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
SB 79 preempts the limit these figures are measured against. This parcel sits within a half mile of a qualifying transit stop in a city that adopted the state standards, so state law overrides the local height and density caps and the governing envelope is a multifamily one, substantially larger than the city's single-family allowance. Read the score, class and headroom above as describing the municipal rule only, not this parcel's ceiling. Confirm the city's adopted SB 79 implementation before underwriting.
Existing home already uses most of the allowable floor area, little expansion headroom. The city’s single-family rule allows roughly 840 sqft of gross floor area on this lot.
Screening estimate comparing existing living area to the city's single-family floor-area limit, which SB 79 preempts on this parcel. 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
Spruce Elementary
South San Francisco Unified
Parkway Heights Middle
South San Francisco Unified
South San Francisco High
South San Francisco 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
78/100
Based on recent sales velocity and local demand in 94080.
Flippability Score
45/100
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.
SB 79 governs this parcel. It sits within a half mile of a qualifying transit stop in a city that adopted the state standards, so state law preempts the local height and density limits and the real ceiling here is a multifamily one, well above what the city's single-family rule allows. The figures below model a detached rebuild, which is not the play on this lot — we don't quote a return on it. Check the city's adopted SB 79 implementation before you underwrite.
Median of 12 recent single-family sales in South San Francisco (94080): $1,059/sqft, plus 5% because new houses sold at a median 1.07x their comps across 239 real rebuilds. Sized within 25% of the 900 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
Warning: Project is mathematically underwater.
Recent Comparables (South San Francisco 94080)
Sized to the modelled 900 sqft build: sales within 25% of it. Smaller houses sell for more per foot, so pricing a rebuild off them overstates resale.