$1,798,000
131 Charles St, Sunnyvale 94086
AddressIntel AI Briefing
With the existing 1,000 sqft home already renovated, the optimal play is stealth density: primary + ADU + JADU to preserve the updated structure while maximizing rental yield. A teardown-and-mansionize or SB 9 lot split is heavily challenged by liquefaction risk, which acts as a costly foundation blocker. However, the high-income neighborhood demographics ($195,673 median household income) support a strong valuation ceiling for any added square footage.
Property Permit History
| Date | Project Type | Status | Valuation | Contractor |
|---|---|---|---|---|
| 2026-07-29 | Electrical | ISSUED | -- | Unknown |
Recent Neighborhood Remodeling (Sunnyvale)
Parcel & Zoning Info
ADU Potential
Flag / irregular · Corner lot · ~83 ft frontage × 139 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
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 2,744 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.
Nearby Public Schools
Vargas Elementary
Sunnyvale
Columbia Middle
Sunnyvale
Community Day
Fremont 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
74/100
Based on recent sales velocity and local demand in 94086.
Flippability Score
45/100
Measures neighborhood renovation density vs. recent permits on this property.
Bidding War Prob.
28%
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 2,744 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 (94086): $1,259/sqft. Sized within 25% of the 2,700 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 94086)
Sized to the modelled 2,700 sqft build: sales within 25% of it. Smaller houses sell for more per foot, so pricing a rebuild off them overstates resale.