21850 Duncan Rd is a 1,295 square foot house on a 3,010 square foot lot with 2 bedrooms and 1 bathroom. Based on Redfin's Monte Rio data, we estimate the home's value is $458,794.
Single-familyProperty Type
1980Year Built
3,010 sq ftLot Size
$354Est. Price/Sq.Ft.
Source:Public Records
Redfin Estimate
$458,794
$11K since August
Recently sold homes
Estimate history
Homes for sale
This home's estimate is 17.3% lower than the average sale price ($555K) of 6 comparable homes.
As the MLS and public records start to fill up, we'll list the details here.
Year
Property tax
Land + Additions
Assessment*
2025
$1,101 (+4.3%)
$11,760 + $43,719
$55,479
2024
$1,056 (+1.7%)
$11,530 + $42,862
$54,392
2023
$1,038 (+2.2%)
$11,304 + $42,022
$53,326
2022
$1,016 (+1.1%)
$11,083 + $41,199
$52,282
2021
$1,005 (−0.6%)
$10,866 + $40,392
$51,258
2020
$1,011 (−4.9%)
$10,653 + $39,600
$50,253
2019
$1,063 (+34.6%)
$10,544 + $39,194
$49,738
2018
$790 (+2.9%)
$10,338 + $38,426
$48,764
2017
$767 (−1.0%)
$9,938 + $36,935
$46,873
2015
$775 (+1.3%)
$9,744 + $36,211
$45,955
2014
$765 (−5.7%)
$9,410 + $34,970
$44,380
2013
$811 (+4.0%)
$9,410 + $34,970
$44,380
2012
$780 (+1.3%)
$9,368 + $34,812
$44,180
2011
$770 (+0.6%)
$9,185 + $34,130
$43,315
2010
$766 (−0.3%)
$9,005 + $33,461
$42,466
2009
$768 (−5.0%)
$8,938 + $33,211
$42,149
2007
$808
$8,785 + $32,638
$41,423
Tax history for 21850 Duncan Rd
Year
Property tax
Land + Additions
Assessment*
2025
$1,101 (+4.3%)
$11,760 + $43,719
$55,479
2024
$1,056 (+1.7%)
$11,530 + $42,862
$54,392
2023
$1,038 (+2.2%)
$11,304 + $42,022
$53,326
2022
$1,016 (+1.1%)
$11,083 + $41,199
$52,282
2021
$1,005 (−0.6%)
$10,866 + $40,392
$51,258
2020
$1,011 (−4.9%)
$10,653 + $39,600
$50,253
2019
$1,063 (+34.6%)
$10,544 + $39,194
$49,738
2018
$790 (+2.9%)
$10,338 + $38,426
$48,764
2017
$767 (−1.0%)
$9,938 + $36,935
$46,873
2015
$775 (+1.3%)
$9,744 + $36,211
$45,955
2014
$765 (−5.7%)
$9,410 + $34,970
$44,380
2013
$811 (+4.0%)
$9,410 + $34,970
$44,380
2012
$780 (+1.3%)
$9,368 + $34,812
$44,180
2011
$770 (+0.6%)
$9,185 + $34,130
$43,315
2010
$766 (−0.3%)
$9,005 + $33,461
$42,466
2009
$768 (−5.0%)
$8,938 + $33,211
$42,149
2007
$808
$8,785 + $32,638
$41,423
*Taxable value of land and structures on it ("additions") is determined regularly by local assessors and does not affect market price.
Permits
Jun 11, 2016 • Final
Building history record
Construct an addition and perform a remodel on a single-family home.
Addition
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
Basement Information
Basement Sq. Ft: 194
Bathroom Information
# of Full Baths: 1
Fireplace Information
# of Fireplaces: 1
Has Fireplace
Room Information
# of Rooms: 3
Exterior
Exterior Information
Construction Type: Wood/Steel
Building Construction Quality: Average
Property Information
Subdivision Name: MONTE CRISTO SUB #1
Living Sq. Ft: 1,295
Building Sq. Ft: 1,295
# of Stories: 1
Lot Information
# of Buildings: 1
Land Sq. Ft: 3,010
Legal Lot Number: 86
Acres: 0.0691
Zoning Code: RR1
County Use Description: SINGLE FAM DWELLING
Financial
Assessor Information
Assessment Year: 2026
Public facts
Beds: 2
Baths: 1.0
Sq. Ft.: 1,295
Stories: 1.0
Lot Size: 3,010 square feet
Style: Single Family Residential
Year Built: 1980
Year Renovated: —
County: Sonoma County
APN: 094027003000
Home facts updated by county records on Aug 13, 2026
Around this home
Schools
Monte Rio Elementary School
Public K-8 • Assigned • 0.6mi
7/10
Analy High School
Public 9-12 • Assigned • 11.6mi
8/10
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
3/10 Fire Factor
0.15% chance of being in a wildfire in next 30 years
2/10 Heat Factor
7 days above 84° expected this year, 20 days in 30 years
1/10 Wind Factor
Minimal risk of severe winds over next 30 years
9/10 Air Factor
17 unhealthy days expected this year, 19 days in 30 years
Provided by First Street
Historical weather
Monte Rio, CA • 95462
Average low and high temperatures (°F)
59
40
60
43
69
44
66
46
74
49
75
51
73
52
82
53
78
53
75
49
62
45
58
44
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Sun exposure
In this area, properties receive around 10.6 hours in
June and 4.9 hours in December, placing it above the
U.S. average for solar exposure.
10.6 hrs
4.9 hrs
JuneDecember
Provided by Shadowmap
Estimated sale price
$436,000 – $528,000
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