Back to Search
ActiveSingle Family

$4,200,000

640 N San Antonio Rd, Los Altos 94022

Beds3
Baths3
Sqft2,186
DOM4
No Photos Available

AddressIntel AI Briefing

The home is already remodeled and move-in ready, making a teardown-and-mansionize strategy unprofitable. The optimal play is to leverage the stealth density pathways by adding a detached ADU to boost rental potential in a high-income neighborhood.

Property Permit History

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

Recent Neighborhood Remodeling (Los Altos)

Parcel & Zoning Info

APN16723093
Official Lot Sqft4,792
Zoning Code--
SB 9 StatusLikely · up to 4 units
Unlock Pathways
Ministerial ADU Ministerial SB 9 Density Bonus
Entitlement RiskLow (0/100)

ADU Potential

Feasibility Score68/100
Max ADU Units2 (ADU + JADU)
Est. ADU Size1,200 sqft
Existing Coverage45.6%

Flag / irregular · Corner lot · ~62 ft frontage × 210 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 Score12/100
ClassBuilt out
FAR Utilization130% of allowed
Buildable Headroom+0 sqft

Existing home already uses most of the allowable floor area, little expansion headroom. Zoning allows roughly 1,677 sqft of gross floor area on this lot.

Screening estimate comparing existing living area to the city's single-family floor-area limit. FAR rule curated from current municipal code. Source: Los Altos Muni Code 14.06.070/14.08.070/14.10.070/14.12.070 (R1-10/H/20/40, one shared formula) (as of 2026-08-24). 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. 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

Elementary School

Bullis Charter

Santa Clara County Office of Education

0.3 miles away
Middle School

Ardis G. Egan Junior High

Los Altos Elementary

0.3 miles away
High School

Los Altos High

Mountain View-Los Altos Union High

0.5 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

64/100

Based on recent sales velocity and local demand in 94022.

Flippability Score

40/100

Measures neighborhood renovation density vs. recent permits on this property.

Bidding War Prob.

16%

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 1,677 sqft here, less than the 2,186 sqft standing today, so a compliant rebuild would be smaller than the existing house. We don't quote a return on this one. Demolishing generally forfeits the existing non-conforming floor area, so treat it as a remodel or check the local code for what it lets you rebuild.

Median of 12 recent single-family sales in Los Altos (94022): $2,445/sqft. Sized within 25% of the 2,200 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.

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.

Hard Costs$935,000
New Build1,700 sqft
Total Capital Required$5,310,000
Estimated Resale (ARV)$4,156,500
Cost of Sale (5%)-$207,825
Net Proceeds$3,948,675

Projected Profit

-$1,361,325
-25.6% ROI

Warning: Project is mathematically underwater.

Recent Comparables (Los Altos 94022)

Sized to the modelled 2,200 sqft build: sales within 25% of it. Smaller houses sell for more per foot, so pricing a rebuild off them overstates resale.

416 Los Ninos Way

Sold
$5,126,000
Sold: 2026-09-15
Lot: 10,800
Sqft: 1911
$/Sqft: $2,682

624 Tomi Lea St

Sold
$5,500,000
Sold: 2026-09-14
Lot: 9,660
Sqft: 2261
$/Sqft: $2,433

56 Coronado Ave

Sold
$7,550,000
Sold: 2026-09-04
Lot: 18,354
Sqft: 2555
$/Sqft: $2,955

109 Lyell St

Sold
$4,550,000
Sold: 2026-09-02
Lot: 7,500
Sqft: 2095
$/Sqft: $2,172

400 E Edith Ave

Sold
$5,650,000
Sold: 2026-08-31
Lot: 11,250
Sqft: 2619
$/Sqft: $2,157

1020 Via Del Pozo

Sold
$5,580,000
Sold: 2026-08-28
Lot: 10,400
Sqft: 2727
$/Sqft: $2,046

315 W Portola Ave

Sold
$4,908,000
Sold: 2026-08-12
Lot: 12,231
Sqft: 1998
$/Sqft: $2,456

26 Deep Well Ln

Sold
$2,400,000
Sold: 2026-08-07
Lot: 2,704
Sqft: 1840
$/Sqft: $1,304

531 San Felicia Way

Sold
$5,880,000
Sold: 2026-08-06
Lot: 12,150
Sqft: 1954
$/Sqft: $3,009

360 Sunkist Ln

Sold
$5,760,000
Sold: 2026-08-05
Lot: 13,554
Sqft: 1992
$/Sqft: $2,892

99 San Juan Ct

Sold
$4,500,000
Sold: 2026-07-30
Lot: 10,000
Sqft: 1710
$/Sqft: $2,632

400 Patrick Way

Sold
$3,800,000
Sold: 2026-07-24
Lot: 5,805
Sqft: 2209
$/Sqft: $1,720