Bay Area Real Estate Data

Bay Farm Island, Alameda vs Cordelia, Fairfield

Bay Farm Island, Alameda carries an effective property tax rate of 1.22% of assessed value and Cordelia, Fairfield carries 1.18%, both for fiscal year 2025-26. On one identical reference loan the monthly carrying costs are $9,917 and $9,864 — $53 apart, with Cordelia, Fairfield lower. To Oakland City Center at AM peak the fastest published commutes are 20 min by car from Bay Farm Island, Alameda and 60 min by car from Cordelia, Fairfield. Every figure is an objective public metric or arithmetic on one, and names its source.

Bay Farm Island, Alameda (Alameda County) · Cordelia, Fairfield (Solano County)

Side by side
Metric Bay Farm Island, Alameda Cordelia, Fairfield Difference
Median $/sqft (SFR)$750$380+$370
Effective tax rate1.22%1.18%+0.040%
Monthly cost, reference loan$9,917$9,864+$53
FiDi SF (Montgomery St BART) — BART45 min85 min−40 min
FiDi SF (Montgomery St BART) — Ferry35 min95 min−60 min
FiDi SF (Montgomery St BART) — Drive40 min75 min−35 min
Oakland City Center (12th St BART) — BART35 min70 min−35 min
Oakland City Center (12th St BART) — Drive20 min60 min−40 min
Sunnyvale / Mountain View (Sunnyvale Caltrain) — Drive55 min95 min−40 min

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

Put the two side by side and the gap is square footage, not tax: $750 per foot in Alameda (Bay Farm) against $380 in Fairfield (Cordelia). On the same $1,600,000 purchase the monthly separation is only $53, because Alameda (Bay Farm) bills 1.22% and Fairfield (Cordelia) 1.18%.

The house at each price

$1.4M on Bay Farm Island is a 1980s-90s detached home of 1,700-2,000 sq ft with a small lot and two-car garage. The Cordelia sweet spot is $700K-$900K for 2,200-2,800 sq ft built 1995-2010. Posted medians are $750 per square foot in Alameda (Bay Farm) and $380 in Fairfield (Cordelia), a $370 spread.

What the bill looks like

Modelled the same way in both ($1,600,000 purchase, 20% down, 6.5% fixed, $2,400 insurance, dues excluded), Alameda (Bay Farm) totals $9,917 a month at 1.22% and Fairfield (Cordelia) $9,864 at 1.18% — tax lines of $1,627 and $1,573. The Bay Farm lagoon villages carry extra lagoon maintenance on top of base dues. The 1990s Green Valley core in Cordelia largely carries no Mello-Roos.

Getting to work

To FiDi SF (Montgomery St BART): 35 minutes by ferry from Alameda (Bay Farm), 75 by driving from Fairfield (Cordelia) — a 40-minute edge to Alameda (Bay Farm), or 6.7 hours across a ten-trip week. To Oakland City Center (12th St BART): 20 minutes by driving from Alameda (Bay Farm), 60 by driving from Fairfield (Cordelia) — a 40-minute edge to Alameda (Bay Farm), or 6.7 hours across a ten-trip week. Bay Farm has no BART; Coliseum station is a 12-minute drive. Walnut Creek is 35 minutes from Cordelia via I-680.

What the disclosure stack holds

Bay Farm Island is not wildland-urban interface. The flats near Cordelia Junction are not WUI, and Suisun Marsh flood mapping touches the southern edge. 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.

The housing need each answers

Bay Farm answers a townhome-pricing requirement with a flat, short bike commute. Cordelia works for remote work with two Bay drive days a week. The decision is which requirement is load-bearing, because neither submarket satisfies both lists.


Sources. Tax figures come from Alameda County Tax Rates by TRA FY 2025-26; Solano County Tax Rate Book FY 2025-26; City of Fairfield CFD reports, 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. Price per square foot is a trailing median and is not an appraisal. Qualitative detail is the broker's own field observation.

Compare any two submarkets

MetricBay Farm Island, AlamedaCordelia, Fairfield
Median $/sqft (SFR)$750$380
Effective tax rate1.22%1.18%
Monthly cost, reference loan$9,917$9,864
Fastest to FiDi SF (Montgomery St BART)35 min75 min
Fastest to Oakland City Center (12th St BART)20 min60 min
Fastest to Sunnyvale / Mountain View (Sunnyvale Caltrain)55 min95 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.

Cordelia, Fairfield detail

Property tax rate — FY 2025-26
ComponentRate of assessed value
Prop 13 general levy1.000%
County / city voter-approved bonds0.010%
School district measures0.090%
Mello-Roos / CFD assessment0.080%
Effective rate1.18%
Mello-Roos / CFD Yes

Source: Solano County Tax Rate Book FY 2025-26; City of Fairfield CFD reports (Solano 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) — Drive75BART85Ferry95Oakland City Center (12th St BART) — Drive60BART70Sunnyvale / Mountain View (Sunnyvale Caltrain) — Drive95
Cordelia, Fairfield 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 Cordelia, Fairfield: questions and answers

Which has the lower effective property tax rate, Bay Farm Island, Alameda or Cordelia, Fairfield?
Cordelia, Fairfield, at 1.18% of assessed value against 1.22% for fiscal year 2025-26 — a gap of 0.040%. 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 Cordelia, Fairfield?
$53 per month on the identical reference loan: Bay Farm Island, Alameda $9,917, Cordelia, Fairfield $9,864. Cordelia, Fairfield 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 Cordelia, Fairfield?
Bay Farm Island, Alameda. Bay Farm Island, Alameda is 20 min by car; Cordelia, Fairfield is 60 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 Cordelia, Fairfield?
$370 per square foot: Bay Farm Island, Alameda $750, Cordelia, Fairfield $380. Single-family medians, trailing twelve months. A median is not a valuation of any specific property.

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