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$13,000,000

  • For Sale
  • Active
  • Single Family
  • 4 Beds
  • 1 Full Bath
  • 4 Partial Baths
  • 7,099 Sq. Ft.
  • 3 Car Garage
  • Updated 8 days ago
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3621 21st St, Boulder, COVideo Tour of 3621 21st St, Boulder, CO.
Meticulously crafted, masterfully built, and expertly curated with an elevated design, this custom home is a true masterpiece, perfectly situated on a premier lot in the exclusive Carolyn Heights neighborhood, The exquisite design and inspiring architecture of this exceptional residence ensures that every facet embodies luxury, casual elegance, and attention to detail, harmoniously blending wood, glass, stone, and steel to create an ambiance that is both inviting and inspiring. Upon entry, you'll be greeted by soaring ceilings, wide plank white oak flooring, & an open-concept main level bathed in abundant natural light streaming through expansive windows, inviting the outside in. The prodigious living area seamlessly integrates indoor & outdoor spaces, offering a glimpse of the splendid living experience that awaits. The architectural grandeur is showcased w/ a dramatic three-story open-tread wooden staircase, custom steel railings, & illuminated by bespoke lighting. The centerpiece of the home, the gourmet kitchen, boasts an impressive center island, marble & quartz countertops, artisanal tile, custom cabinetry, top-tier chef's appliances, & walk-in pantry. The elegant main floor primary bedroom suite is a tranquil retreat, w/ wall-to-wall windows, a generous walk-in closet w/custom cabinetry. The soothing primary bathroom features premium quality finishes, including designer tile, custom cabinetry, & alluring lighting.The heated pool w/ a tanning shelf, natural stone deck, & automatic pool cover takes center stage in the serene yard. Every aspect of this smart home seamlessly integrates technology, design, & automation to ensure security & convenience, and efficiency. For the discerning owner desiring a residence that embodies casual elegance & architectural interest, w/proximity to vibrant downtown Boulder & nestled in an upscale neighborhood, this property is a rare find that offers an unsurpassed lifestyle.

Full Property Details for 3621 21st St

General

  • Price: $13,000,000
  • Taxes: $55,752 (2024)
  • Status: Active
  • Type: Single Family
  • Source: IRES
  • MLS ID: 1051395
  • Updated: 2/12/2026
  • Added to Site: 9 day(s) ago

Interior

  • Interior Features: Eat-In Kitchen, Cathedral Ceiling(s), Open Floorplan, Pantry, Walk-In Closet(s), Wet Bar, Washer/Dryer Hookup, Kitchen Island, Steam Shower, High Ceilings, Split Bedroom Plan
  • Fireplace: Yes
  • Fireplace(s): Gas, Living Room
  • Appliances: Gas Range, Double Oven, Dishwasher, Refrigerator, Bar Fridge, Washer, Dryer, Microwave, Trash Compactor, Freezer, Gas Bar-B-Q, Disposal, Fire Alarm
  • Flooring: Wood

Rooms

Bathrooms

  • Total Bathrooms: 5
  • Full Bathrooms: 1
  • 3/4 Bathrooms: 3
  • Half Bathrooms: 1
  • Main Floor Baths: 1

Bedrooms

  • Total Bedrooms: 4

Other Rooms

  • Laundry: Sink

Additional Information

  • Pool: Yes
  • Pool Description: Private
  • Security/Safety: Fire Sprinkler System, Security System

Exterior

  • Exterior Features: Sprinkler System, Hot Tub, Heated Garage, Oversized Garage
  • Porch/Patio/Deck: Patio

Parking

  • Garage: Yes
  • Attached garage: Yes
  • Garage Spaces: 3
  • Parking Features: Garage Door Opener, Attached
  • Garage Description: Attached

Location

  • Area: Boulder
  • County: Boulder
  • Subdivision: Carolyn Heights

School Information

  • School District: Boulder Valley Dist RE2
  • Elementary School: Crest View
  • Middle School: Centennial
  • High School: Boulder

Heating & Cooling

  • Cooling Type: Central Air
  • Heating Type: Radiant

Utilities

  • Gas: Yes
  • Gas: Xcel
  • Sewer: Public Sewer
  • Water: City
  • Utility Description: Natural Gas Available, Electricity Available, Cable Available, High-Speed Internet Available

Structural Information

  • Architectural Style: Contemporary
  • Construction: Frame, Brick, Block, Stone
  • Exterior Const.: Frame, Brick, Block, Stone
  • Basement: Yes
  • Basement Desc.: Full
  • Roof: Composition
  • Windows: Window Coverings
  • Square Feet: 7,099
  • Sq. Ft. Source: Other
  • Living Area: 6,300 Sq. Ft.
  • Year Built: 2021

Lot Features

  • Lot Size (Acres): 0.66
  • Lot Size (Sq. Ft.): 28,700
  • Frontage: City Street
  • Street/Road Desc.: Asphalt
  • Fence: Yes
  • Lot Features: Wooded, Evergreen Trees, Deciduous Trees, Native Grass, Level, House Faces East, City Limits, Paved
  • Potential Use: Single-Family
  • Zoning: RES
  • Fencing (Description): Fenced, Dog Run/Kennel

Green Features

  • Energy Efficient: Southern Exposure, Windows, Photovoltaic Owned

Financial Considerations

  • Tax Amount: $55,752
  • Tax Year: 2024
  • Terms: Cash, Conventional

Disclosures and Reports

  • Special Conditions: Private Owner
  • Exclusions: Personal Property and Artwork
  • Property ID: R0004965

Listed by Compass - Boulder (303) 487-5472

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Listing agent

— 3621 21st St —

  • Compass - Boulder

    303-487-5472

3034756097

Get Pre-Approved Today

Be ready to buy your new home!

with our affiliated lender
NMLS#: 1598647

Get Pre-Approved

Be ready to buy your new home!

with our affiliated lender
NMLS#: 1598647

Get Pre-Approved

Schools serving 3621 21st St

School District:Boulder Valley School District Re-2
NameGradesDistance
Columbine Elementary School, Boulder, CO
3130 Repplier Street, Boulder, CO 80304
PK-50.6 mi
Centennial Middle School, Boulder, CO
2205 Norwood Avenue, Boulder, CO 80304
6-80.3 mi
Boulder High School
1604 Arapahoe Avenue, Boulder, CO 80302
9-121.8 mi
Disclaimer: School attendance boundaries provided by Pitney Bowes and are for reference only. Contact the school directly to verify enrollment eligibility.

Price & Sales History for 3621 21st St Get Price Alerts and Save Property

Date
Details
Price
Change
Source
2/11/2026
Listed
$13,000,000
30%
MLS
6/13/2022
Sold
$10,000,000
—
Public Record
Get Price Alerts and Save Property
Disclaimer: Historical sales information is derived from public records provided by the county offices. Information is not guaranteed and should be independently verified.

Tax History for 3621 21st St

Year
Property Taxes
Change
Tax Assessment
Change
2025
$56,445
1%
$591,975
-7%
2024
$55,752
2%
$634,376
-1%
2023
$54,784
294%
$638,062
294%
2021
$13,922
-5%
$161,747
3%
2022
$14,600
5%
$157,223
—
2021
$13,922
3%
$156,993
—
2019
$13,456
5%
$156,993
6%
2018
$12,859
3%
$148,313
—
2017
$12,456
-2%
$148,313
1%
2016
$12,664
6%
$146,297
—
2015
$11,992
18%
$146,297
24%
2014
$10,145
2%
$117,999
—
2013
$9,921
—
$117,999
—
View All
Disclaimer: Historical tax information is derived from public records provided by the county offices. Information is not guaranteed and should be independently verified.

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NMLS#: 1598647

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Listed by Compass - Boulder (303) 487-5472

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3621 21st St, Boulder, CO 80304 (MLS# 1051395) is a Single Family property with 4 bedrooms, 1 full bathroom and 4 partial bathrooms. 3621 21st St is currently listed for $13,000,000 and was received on February 11, 2026. Want to learn more about 3621 21st St? Do you have questions about finding other Single Family real estate for sale in Boulder? You can browse all Boulder real estate or contact a Coldwell Banker agent to request more information.

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