3500 Keystone Loop is a 2,033 square foot house on a 7,500 square foot lot with 3 bedrooms and 2 bathrooms. - it last sold on May 19, 2006 for $585,000. Based on Redfin's Discovery Bay data, we estimate the home's value is $711,303.
Single-familyProperty Type
2003Year Built
7,500 sq ftLot Size
$350Est. Price/Sq.Ft.
2 car garageParking
Source:Public Records
Redfin Estimate
$711,303
$126K since sold in May 2006$6,000 since October
Recently sold homes
Estimate history
Homes for sale
This home's estimate is 2.1% higher than the average sale price ($697K) of 6 comparable homes.
bridgeMLS, Bay East AOR, or Contra Costa AOR #40161129
Apr 29, 2006
Listing Removed
—
Year
Property tax
Land + Additions
Assessment*
2026
$9,505 (+0.2%)
$225,979 + $435,021
$661,000
2025
$9,485 (+3.4%)
$225,979 + $435,021
$661,000
2024
$9,177 (+1.8%)
$230,082 + $442,918
$673,000
2023
$9,015
$230,000 + $443,000
$673,000
2022
$9,007 (+16.2%)
$224,955 + $433,045
$658,000
2021
$7,751 (+5.0%)
$224,955 + $433,045
$658,000
2020
$7,383 (−0.3%)
$187,690 + $361,310
$549,000
2019
$7,402 (+10.1%)
$175,383 + $337,617
$513,000
2018
$6,723 (+8.5%)
$175,383 + $337,617
$513,000
2017
$6,199 (+5.8%)
$144,614 + $278,386
$423,000
2016
$5,859 (+6.3%)
$144,614 + $278,386
$423,000
2015
$5,512 (−3.0%)
$141,879 + $273,121
$415,000
2014
$5,681 (+34.3%)
$139,828 + $269,172
$409,000
2013
$4,229 (+9.6%)
$139,828 + $269,172
$409,000
2012
$3,859 (+0.4%)
$95,213 + $183,287
$278,500
2011
$3,842 (+2.6%)
$83,931 + $161,569
$245,500
2010
$3,745 (−5.1%)
$83,931 + $161,569
$245,500
2009
$3,946 (−28.3%)
$83,931 + $161,569
$245,500
2008
$5,505
$92,308 + $177,692
$270,000
Tax history for 3500 Keystone Loop
Year
Property tax
Land + Additions
Assessment*
2026
$9,505 (+0.2%)
$225,979 + $435,021
$661,000
2025
$9,485 (+3.4%)
$225,979 + $435,021
$661,000
2024
$9,177 (+1.8%)
$230,082 + $442,918
$673,000
2023
$9,015
$230,000 + $443,000
$673,000
2022
$9,007 (+16.2%)
$224,955 + $433,045
$658,000
2021
$7,751 (+5.0%)
$224,955 + $433,045
$658,000
2020
$7,383 (−0.3%)
$187,690 + $361,310
$549,000
2019
$7,402 (+10.1%)
$175,383 + $337,617
$513,000
2018
$6,723 (+8.5%)
$175,383 + $337,617
$513,000
2017
$6,199 (+5.8%)
$144,614 + $278,386
$423,000
2016
$5,859 (+6.3%)
$144,614 + $278,386
$423,000
2015
$5,512 (−3.0%)
$141,879 + $273,121
$415,000
2014
$5,681 (+34.3%)
$139,828 + $269,172
$409,000
2013
$4,229 (+9.6%)
$139,828 + $269,172
$409,000
2012
$3,859 (+0.4%)
$95,213 + $183,287
$278,500
2011
$3,842 (+2.6%)
$83,931 + $161,569
$245,500
2010
$3,745 (−5.1%)
$83,931 + $161,569
$245,500
2009
$3,946 (−28.3%)
$83,931 + $161,569
$245,500
2008
$5,505
$92,308 + $177,692
$270,000
*Taxable value of land and structures on it ("additions") is determined regularly by local assessors and does not affect market price.
Zoning and permits
Zoning
Permits
P-1
Planned Unit District
A large-scale integrated development or a general plan special area of concern provides an opportunity for, and requires cohesive design when flexible regulations are applied; whereas the application of conventional regulation, designed primarily for individual lot development, to a large-scale development or special area may create a monotonous and inappropriate neighborhood. The planned unit district is intended to allow diversification in the relationship of various uses, buildings, structures, lot sizes and open space while insuring substantial compliance with the general plan and the intent of the county code in requiring adequate standards necessary to satisfy the requirements of the public health, safety and general welfare. These standards shall be observed without unduly inhibiting the advantages of large-scale site or special area planning.
Permitted uses
Include but are not limited to:
Housing-Single unit
Jul 30, 2003 • Final
Building/residential/r/new single family-duplex
New construction
Permit history is from public records and may be incomplete or inaccurate. Redfin and its agents make no representations about the property condition or permit status. Buyers should independently verify all information.
Property details
Interior
Room Information
# of Rooms: 7
Exterior
Property Information
Living Sq. Ft: 2,033
Ground Floor Sq. Ft: 2,033
Building Sq. Ft: 2,033
# of Stories: 1
Legal Description: T8430 L35
Parking & Garage Information
Garage/Parking Sq. Ft: 482
Lot Information
# of Buildings: 1
Land Sq. Ft: 7,500
Legal Lot Number: 35
Acres: 0.1722
Zoning Code: P-1
County Use Description: SINGLE FAMILY DETACHED WITH MA
Financial
Assessor Information
Assessment Year: 2026
Public facts
Beds: 3
Baths: 2.0
Sq. Ft.: 2,033
Stories: 1.0
Lot Size: 7,500 square feet
Style: Single Family Residential
Year Built: 2003
Year Renovated: 2004
County: Contra Costa County
APN: 0114210354
Home facts updated by county records on Oct 30, 2026
Around this home
Schools
K - 12
Preschool & daycare
Timber Point Elementary School
Public K-5 • Assigned • 0.5mi
6/10
Excelsior Middle School
Public 6-8 • Assigned • 2.8mi
4/10
Liberty High School
Public 9-12 • Assigned • 4.5mi
7/10
Provided by GreatSchools
Lifestyle
Provided by Walk Score and Local Logic
Climate risks
1/10 Flood Factor
Minimal risk of a flood reaching the building in the next 30 years
2/10 Fire Factor
0.00% chance of being in a wildfire in next 30 years
6/10 Heat Factor
7 days above 102° expected this year, 15 days in 30 years
1/10 Wind Factor
Minimal risk of severe winds over next 30 years
9/10 Air Factor
20 unhealthy days expected this year, 21 days in 30 years
Provided by First Street
Historical weather
Discovery Bay, CA • 94505
Average low and high temperatures (°F)
59
39
63
44
72
49
73
49
82
55
89
58
92
60
95
62
88
62
75
54
64
46
56
43
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Sun exposure
In this area, properties receive around 12.6 hours in
June and 4.7 hours in December, placing it above the
U.S. average for solar exposure.
12.6 hrs
4.7 hrs
JuneDecember
Provided by Shadowmap
Estimated sale price
$676,000 – $818,000
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