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ActiveSingle Family

$1,799,000

18 Hillbarn Ct, San Mateo 94403

Beds2
Baths2
Sqft1,530
DOM12
No Photos Available

AddressIntel AI Briefing

The optimal play is stealth density: primary + ADU + JADU, taking advantage of an exceptional 96/100 ADU feasibility score on a 7,087 sqft lot. A full teardown is discouraged because the existing home has already been remodeled, conserving immediate asset value. This strategy maximizes rental yield without incurring the massive capital expenditure of a new build.

Property Permit History

No permit history found directly associated with this property's address.

Recent Neighborhood Remodeling (San Mateo)

2026-08-04520 BUCKNELL DR SAN MATEO 94402-3250 CA
Single Family (Addition) - Add/Alter
$275,473Issued
2026-08-04725 E 16TH AVE SAN MATEO 94402-2131 CA
Single Family (Alteration/Repair) - Kitchen & Bath Remodel (Flat)
$20,388Issued
2026-08-043131 SUNSET TER SAN MATEO 94403-3846 CA
Single Family (Addition) - Add/Alter
$79,365Issued
2026-08-03116 POWELL ST SAN MATEO CA 94401-2033
Single Family (Addition) - Add/Alter
$268,896Issued
2026-08-032831 MONTEREY ST Unit: B SAN MATEO CA 94403
Single Family (New) - New
$123,326Issued
2026-07-31908 9TH AVE SAN MATEO CA 94402-1434
Single Family (Alteration/Repair) - Kitchen & Bath Remodel (Flat)
$17,000Issued

Parcel & Zoning Info

APN042262100
Official Lot Sqft7,087
Zoning CodeNO DATA ASSIGNED
SB 9 StatusLikely · up to 4 units
Unlock Pathways
Ministerial ADU Ministerial SB 9 Density Bonus
Entitlement RiskLow (0/100)

ADU Potential

Feasibility Score96/100
Max ADU Units2 (ADU + JADU)
Est. ADU Size1,200 sqft
Existing Coverage21.6%

Flag / irregular · Corner lot · ~107 ft frontage × 133 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

Redevelopment Score62/100
ClassTeardown candidate
FAR Utilization48% of allowed
Buildable Headroom+1,687 sqft

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 3,217 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

X
Area of minimal flood hazard.

Fire Severity

None
Not in a mapped state fire severity zone.

Liquefaction

No
Not in a mapped liquefaction zone.

Fault Zone

No
Not in a mapped Alquist-Priolo 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

Elementary School

Central Elementary

Belmont-Redwood Shores Elementary

0.6 miles away
Middle School

Abbott Middle

San Mateo-Foster City

0.9 miles away
High School

Hillsdale High

San Mateo Union High

1.1 miles away

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

84/100

Based on recent sales velocity and local demand in 94403.

Flippability Score

60/100

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 3,217 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 6 recent single-family sales in 94403: $1,332/sqft.

Hard Costs$1,280,000
New Build3,200 sqft
Total Capital Required$3,254,000
Estimated Resale (ARV)$4,262,400

Projected Profit

$1,008,400
31.0% ROI

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