Bay Area Real Estate Data

Bay Farm Island, Alameda vs Piedmont

Bay Farm Island, Alameda carries an effective property tax rate of 1.22% of assessed value and Piedmont carries 1.25%, both for fiscal year 2025-26. On one identical reference loan the monthly carrying costs are $9,917 and $9,960 — $43 apart, with Bay Farm Island, Alameda lower. To Oakland City Center at AM peak the fastest published commutes are 20 min by car from Bay Farm Island, Alameda and 15 min by car from Piedmont. Every figure is an objective public metric or arithmetic on one, and names its source.

Bay Farm Island, Alameda (Alameda County) · Piedmont (Alameda County)

Side by side
Metric Bay Farm Island, Alameda Piedmont Difference
Median $/sqft (SFR)$750$1,200−$450
Effective tax rate1.22%1.25%−0.032%
Monthly cost, reference loan$9,917$9,960−$43
FiDi SF (Montgomery St BART) — BART45 min35 min+10 min
FiDi SF (Montgomery St BART) — Drive40 min35 min+5 min
Oakland City Center (12th St BART) — BART35 min20 min+15 min
Oakland City Center (12th St BART) — Drive20 min15 min+5 min
Sunnyvale / Mountain View (Sunnyvale Caltrain) — Drive55 min65 min−10 min

Difference is Bay Farm Island, Alameda minus Piedmont. Sources are cited on each submarket page.

Alameda (Bay Farm) is the cheaper foot by $450, 38% below Piedmont. What that buys is a different house, not a different bill: at $1,600,000 the two are $43 apart a month at 1.22% and 1.25%.

Square footage per dollar

Piedmont comps run $1,000-$1,150 per square foot; the Estates and Hampton sections start at $3M. Against that, bay Farm comps run $800-$900 per square foot detached and the high $600s for lagoon townhomes. Posted medians are $750 per square foot in Alameda (Bay Farm) and $1,200 in Piedmont, a $450 spread.

Carrying $1,600,000 in each

Against an identical $1,600,000 note at 6.5% with 20% down and $2,400 a year of coverage, Alameda (Bay Farm) totals $9,917 a month at 1.22% and Piedmont $9,960 at 1.25% — tax lines of $1,627 and $1,669. The Bay Farm lagoon villages carry extra lagoon maintenance on top of base dues. Piedmont Unified's school support tax runs $3,000-$4,500 a year, scaled by lot size.

Getting to work

To Sunnyvale / Mountain View (Sunnyvale Caltrain): 55 minutes by driving from Alameda (Bay Farm), 65 by driving from Piedmont — a 10-minute edge to Alameda (Bay Farm), or 1.7 hours across a ten-trip week. To Oakland City Center (12th St BART): 20 minutes by driving from Alameda (Bay Farm), 15 by driving from Piedmont — a 5-minute edge to Piedmont, or 0.8 hours across a ten-trip week. Doolittle to I-880 or the Posey Tube gets Bay Farm to Oakland City Center in 15 minutes off-peak; the tube backs up 7:30-9:00. Door to door from Piedmont to FiDi is 40-50 minutes.

Fire, flood and the premium

Parts of Bay Farm sit in FEMA AE zones where lenders require flood insurance at $600-$1,500 a year. Hayward Fault distance, 1920s foundations and sewer lateral compliance are Piedmont's standing disclosures. Pull the parcel's own mapping — CAL FIRE severity zone, FEMA flood panel, CGS liquefaction zone — and get a written quote before the contingency date.

Which search this actually is

Bay Farm answers a townhome-pricing requirement with a flat, short bike commute. Piedmont works for a car or transbay-bus commute rather than a walk-to-BART one. Rank the requirements first; the pair rarely splits on anything except the one that is non-negotiable.


Sources. Tax figures come from Alameda County Tax Rates by TRA FY 2025-26, composited in build/assets/metrics.json. They are county-level and not yet verified at the TRA, so the parcel's bill governs. Travel times are AM-peak door-to-door estimates from data/commute/static.csv. Median price per foot is a trailing figure, not a valuation, and the local detail comes from the broker's own transactions.

Compare any two submarkets

MetricBay Farm Island, AlamedaPiedmont
Median $/sqft (SFR)$750$1,200
Effective tax rate1.22%1.25%
Monthly cost, reference loan$9,917$9,960
Fastest to FiDi SF (Montgomery St BART)35 min35 min
Fastest to Oakland City Center (12th St BART)20 min15 min
Fastest to Sunnyvale / Mountain View (Sunnyvale Caltrain)55 min65 min

Same reference loan on both sides; the tax line is the only variable. Commute figures are door-to-door AM-peak estimates. Sources are listed on each submarket page.

Bay Farm Island, Alameda detail

Property tax rate — FY 2025-26
ComponentRate of assessed value
Prop 13 general levy1.000%
County / city voter-approved bonds0.042%
School district measures0.178%
Effective rate1.22%
Mello-Roos / CFD None recorded

Source: Alameda County Tax Rates by TRA FY 2025-26 (Alameda County), composited in build/assets/metrics.json. Tax Rate Area not yet verified parcel-by-parcel — confirm the rate on the parcel’s own tax bill.

FiDi SF (Montgomery St BART) — Ferry35Drive40BART45Oakland City Center (12th St BART) — Drive20BART35Sunnyvale / Mountain View (Sunnyvale Caltrain) — Drive55
Bay Farm Island, Alameda door-to-door commute, AM peak, in minutes. Rail and ferry in blue, driving in grey. Source: data/commute/static.csv.

Piedmont detail

Property tax rate — FY 2025-26
ComponentRate of assessed value
Prop 13 general levy1.000%
County / city voter-approved bonds0.042%
School district measures0.210%
Effective rate1.25%
Mello-Roos / CFD None recorded

Source: Alameda County Tax Rates by TRA FY 2025-26 (Alameda County), composited in build/assets/metrics.json. Tax Rate Area not yet verified parcel-by-parcel — confirm the rate on the parcel’s own tax bill.

FiDi SF (Montgomery St BART) — BART35Drive35Oakland City Center (12th St BART) — Drive15BART20Sunnyvale / Mountain View (Sunnyvale Caltrain) — Drive65
Piedmont door-to-door commute, AM peak, in minutes. Rail and ferry in blue, driving in grey. Source: data/commute/static.csv.

Bay Farm Island, Alameda vs Piedmont: questions and answers

Which has the lower effective property tax rate, Bay Farm Island, Alameda or Piedmont?
Bay Farm Island, Alameda, at 1.22% of assessed value against 1.25% for fiscal year 2025-26 — a gap of 0.030%. Rates are composited from county tax rate books; each parcel bill governs.
How much do monthly carrying costs differ between Bay Farm Island, Alameda and Piedmont?
$43 per month on the identical reference loan: Bay Farm Island, Alameda $9,917, Piedmont $9,960. Bay Farm Island, Alameda is lower. Principal and interest are held constant, so the difference is the tax line. Arithmetic only.
Which has the shorter commute to Oakland City Center, Bay Farm Island, Alameda or Piedmont?
Piedmont. Bay Farm Island, Alameda is 20 min by car; Piedmont is 15 min by car. Door-to-door, AM peak. Source: data/commute/static.csv.
What is the price per square foot difference between Bay Farm Island, Alameda and Piedmont?
$450 per square foot: Bay Farm Island, Alameda $750, Piedmont $1,200. Single-family medians, trailing twelve months. A median is not a valuation of any specific property.

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