3639 21st St, Boulder, CO 80304 Property Records

Boulder County property record for 3639 21st St, Boulder, CO 80304

Property Summary

Property Type	Single Family Home
Details	4 bd · 5.25 ba · 7,666 sqft · built 2007
Lot Size	0.685 acres (29,837 sqft)
Owner	2 Individual Names on Record
Last Sale	$4,200,000 (Feb 2021)
Tax Bill	$39,579 (2025)
Deeds & Mortgages	Apr 2018 Mortgage Jun 2019 Mortgage + 3 more
Flood Zone	Zone X (minimal risk)
APN	`1463-19-1-31-001`

Property Details

APN / Parcel Number

Primary APN	`1463-19-1-31-001`
Alternative APNs	`R0105364` `0105364`

Interior

Bedrooms	4 Beds
Full Baths	5.25 Baths
Half Baths	6 Half Baths
Total Rooms	12 Rooms
Stories	2 Stories
Building Area	7,666 sqft Living Area
Gross Area	9,114 sqft
1st Floor Area	3,602 sqft
Upper Floors Area	2,099 sqft
Basement Area	2,114 sqft
Finished Basement	1,799 sqft
Unfinished Basement	315 sqft
Interior Walls	Wallboard/Drywall

Exterior

Year Built	Built 2007
Effective Year Built	Effective 2015
Architectural Style	A-Frame
Exterior Material	Combination
Construction Type	Frame
Roof Material	Concrete
Lot Area	29,837 sqft (0.685 acres)
Garage Type	Attached
Garage Area	1,133 sqft
Parking Spaces	4 Parking Spaces

Exterior Amenities

Porch	Porch
Porch Area	182 sqft
Deck Area	46 sqft
Patio Area	1,640 sqft

Utilities, Heating & Cooling

Cooling System	Central
Heating System	Forced Air with A/C

Location & Zoning

Account Number	R0105364
Street Address	3639 21ST ST
City	BOULDER
State	CO
Zip	80304-1607
Property Category	Residential
Property Type	Residential > Single Family > Home
Legal Description	LOT 2 21ST/LINDEN
Legal Range	70
Legal Township	1N
Legal Section	19
Legal Subdivision	21ST/LINDEN SUB - BO
Legal Block	1
Legal Lot Number	2
Jurisdiction	BOULDER CO
Township / Civil Division	BOULDER
Census Block Group	1
Census Block	1000
Census Tract	12103

Owner

Source: Boulder County records, as of September 18, 2026

Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.

Owner of Record	2 Individual Names on Record
Mailing Address	3639 21ST ST, BOULDER, CO 80304-1607
Occupancy	Owner Occupied
Owner Type	Individual
Vesting	Joint Tenants

Deeds, Mortgages & Sale History

Date	Document
Apr 3, 2018	Deed of Trust, Mortgage · Commercial Mortgage GREAT WESTERN BANK
Jun 17, 2019	Deed of Trust, Mortgage · ARM CHERRY CREEK MORTGAGE CO INC
Oct 28, 2019	Deed of Trust, Mortgage · Commercial Mortgage GREAT WESTERN BANK
Apr 15, 2021	Deed of Trust, Mortgage · Conventional Mortgage BANK OF AMERICA NA
Feb 16, 2021	Warranty Deed, Transfer LAND TITLE GUARANTEE

Assessor's Deed Record

Deed Names	2 Names on Deed
Last Sale	Feb 16, 2021 · Amount on Record
Deed Sale	Feb 16, 2021 · Amount on Record
Prior Sale	Oct 7, 2013 · Amount on Record
Deed Document Number	20213858782
Prior Transfer Date	May 28, 1998
Prior Transfer Doc	0001812720
Record Updated	Oct 29, 2026

April 2018: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	BOULDER CO
Property Address	3639 21ST ST, BOULDER, CO 80304-1607
Transaction Type	Mortgage
Record Updated	Mar 31, 2022

Transferred To (Grantee/Buyer)

Name	Verified Name

Mortgage

Document Number	0003648666
Date	Apr 3, 2018
Instrument	3648666

Lender

Name	GREAT WESTERN BANK
Type	Bank
Address	BOULDER, CO 80302

Agreement

Type	Commercial Mortgage
Amount	Amount Recorded
Term	59 Months
Due	Mar 10, 2023

Interest

Rate Type	Adjustable Rate
Change Frequency	Monthly

June 2019: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	BOULDER CO
Property Address	3639 21ST ST, BOULDER, CO 80304-1607
Transaction Type	Mortgage
Record Updated	Mar 31, 2022
Title Company	HERITAGE TITLE CO

Transferred To (Grantee/Buyer)

Name	Verified Name

Mortgage

Document Number	0003718530
Date	Jun 17, 2019
Instrument	3718530

Lender

Name	CHERRY CREEK MORTGAGE CO INC
Type	Mortgage Company
Address	ENGLEWOOD, CO 80111

Agreement

Type	ARM
Amount	Amount Recorded
Term	361 Months
Due	Jul 1, 2049

Interest

Rate Type	Adjustable Rate
Rate	3.87%
Adjustable	Adjustable Rate Rider
Type Change Date	Jul 1, 2024
Change Frequency	Annually
Min Rate At Change	2.25%
Max Rate At Change	8.87%
Index	1-Year LIBOR
Max Rate	8.87%

October 2019: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	BOULDER CO
Property Address	3639 21ST ST, BOULDER, CO 80304-1607
Transaction Type	Mortgage
Record Updated	Mar 31, 2022

Transferred To (Grantee/Buyer)

Name	Verified Name

Mortgage

Document Number	0003745331
Date	Oct 28, 2019
Instrument	3745331

Lender

Name	GREAT WESTERN BANK
Type	Bank
Address	BOULDER, CO 80302

Agreement

Type	Commercial Mortgage
Amount	Amount Recorded
Term	60 Months
Due	Oct 25, 2024

Interest

Rate Type	Adjustable Rate
Change Frequency	Monthly

April 2021: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	BOULDER CO
Property Address	3639 21ST ST, BOULDER, CO 80304-1607
Transaction Type	Mortgage
Record Updated	Mar 31, 2022

Transferred To (Grantee/Buyer)

Name	Verified Name

Mortgage

Document Number	0003877182
Date	Apr 15, 2021
Instrument	3877182

Lender

Name	BANK OF AMERICA NA
Type	Bank
Address	CHARLOTTE, NC 28255

Agreement

Type	Conventional Mortgage
Amount	Amount Recorded
Term	361 Months
Due	May 1, 2051

February 2021: Warranty Deed, Transfer

Document Type	Warranty Deed
Jurisdiction	BOULDER CO
Recording Date	Feb 16, 2021
Property Address	3639 21ST ST, BOULDER, CO 80304-1607
Document Number	0003858782
Instrument Date	Feb 11, 2021
Instrument	3858782
Transaction Type	Transfer
Record Updated	Mar 31, 2022
Title Company	LAND TITLE GUARANTEE

Transaction

Amount	Amount Recorded
Tax	$420.00
Amount Accuracy	Full Amount Stated
Additional	Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name
Address	3639 21ST ST, 3639, BOULDER, CO 80304-1607

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Joint Tenants
Address	3639 21ST ST, BOULDER, CO 80304-1607

Tax Assessment & Valuation

Source: Boulder County assessment roll, as of September 18, 2026

Property Jurisdictions

Type	Name
State	Colorado
County	Boulder County
Municipality	Boulder City
Unified School District	Boulder Valley School District RE-2 (PK - 12)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value	Assessed Market Value
2026		$446,869 (+7.65%) Land $73,318 Building $373,551	$6,641,600 (-) Land $1,148,200 Building $5,493,400
2025	$39,579.00 (+14.4%)	$415,101 (+2.67%) Land $71,763 Building $343,338	$6,641,600 (+10.06%) Land $1,148,200 Building $5,493,400
2023	$34,598.00 (+15.13%)	$404,318 (+24.94%) Land $74,953 Building $329,365	$6,034,600 (+29.6%) Land $1,118,700 Building $4,915,900
2022	$30,051.00	$323,606 Land $59,944 Building $263,662	$4,656,200 Land $862,500 Building $3,793,700

Assessed value and assessed market value are set for property tax purposes, not market price estimates; both are a fraction of this property's market value.

Flood

Source: FEMA National Flood Hazard Layer, effective October 14, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026

FEMA Flood Zone	Zone X minimal risk
Flood Insurance Requirement	Not required lenders may require it
Flood Insurance Cost	Premium on Record median of 18 policies
Community Rating System	Class 5 (25% premium discount)
Nearby Flood Policies	18 in force
Nearby Flood Claims	3 (2013)
Claims Outside the SFHA	3 of 3
Most Recent Claim	Sep 2013 · Severe Storms, Flooding, Landslides, And Mudslides
Claims by Event	Severe Storms, Flooding, Landslides, And Mudslides, Sep 2013 · 3 claims

Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.

Wildfire

Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024

Wildfire Risk	Low lower than 80% of the US · lower than 91% of Colorado
Wildfire Likelihood	0.01% annual chance
Exposure	Direct burnable vegetation

Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.

Drinking Water

Source: EPA Safe Drinking Water Information System, as of September 2026

Water System	CITY OF BOULDER serves 166,080 people · EPA ID CO0107152
Water Source	Surface water
Last State Inspection	Sep 2024
Lead	2 ppb (2023–2025) action level 15 ppb

Violations Reported to EPA

Water Quality	Haloacetic acids resolved · Jul 2017
Treatment and Procedure	None last 10 years
Monitoring and Reporting	1 last 3 years

Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes.

Internet Providers

Source: FCC Broadband Data Collection, based on 482 locations within half a mile, as of December 31, 2025

Provider	Max Down / Up (Mbps)
CenturyLink Fiber · DSL in parts of the area	8,000 / 8,000
Ayva Networks Fixed Wireless	2,500 / 2,500
Xfinity Cable	2,000 / 250
LiveWireNet Fixed Wireless	250 / 100

May also be available: T-Mobile, Verizon.

Cell Coverage

5G (outdoors only) and 4G LTE

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