$1,898,000
813 San Petronio Ave, Sunnyvale 94085
AddressIntel AI Briefing
Because SB 9 is blocked by the active flood zone hazard, the optimal play is stealth density: primary + ADU + JADU. Utilizing ministerial ADU pathways allows developers to bypass the split restrictions while adding valuable rental square footage. Designing elevated accessory structures will be critical to mitigate the local flood and liquefaction risks.
Property Permit History
Recent Neighborhood Remodeling (Sunnyvale)
Parcel & Zoning Info
ADU Potential
Standard lot · Corner lot · ~58 ft frontage × 101 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
Meaningful unused floor-area headroom under current zoning, room to add square footage. Zoning allows roughly 2,352 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: Sunnyvale Muni Code Ch. 19.32, Table 19.32.020 (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
San Miguel Elementary
Sunnyvale
Columbia Middle
Sunnyvale
Mission Early College High
Santa Clara 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
65/100
Based on recent sales velocity and local demand in 94085.
Flippability Score
45/100
Measures neighborhood renovation density vs. recent permits on this property.
Bidding War Prob.
32%
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 2,352 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 Sunnyvale (94085): $1,143/sqft. Sized within 25% of the 2,400 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 (Sunnyvale 94085)
Sized to the modelled 2,400 sqft build: sales within 25% of it. Smaller houses sell for more per foot, so pricing a rebuild off them overstates resale.