Exquisite secluded sanctuary in the heart of Carolyn Heights. Tucked into one of Boulder's most prestigious enclaves, this estate offers a rare fusion of luxury, privacy, and relaxed sophistication. Set on a serene, tree-lined .81-acre level lot, this 7-bedroom, 5-bathroom oasis is where inspired design meets effortless living. Stunning views of the Flatirons awaken you each morning from your bed. Those same views tease your senses from the expansive patios with fully retractable doors that blur the lines from inside to outside. Bathed in natural light from soaring windows and skylights, every detail has been thoughtfully curated. Custom walnut doors and paneling welcome you into the home and invite you to explore. The chef's kitchen is a showstopper-featuring custom cabinetry, an oversized marble island, and top-of-the-line Thermador appliances. The open-concept layout flows seamlessly into a lush backyard oasis, perfect for gatherings or quiet moments of retreat by the fire pit. The primary suite is a haven unto itself with vaulted ceilings, a spa-inspired bath, spacious walk-in closet, and private deck access. With multiple flexible living spaces-including a dedicated home office and media room, this home is ready to adapt to your every need. Located minutes from North Boulder's best hiking trails, cycling routes, farmers markets, and local eateries-yet nestled in the peaceful privacy of a mature, sought-after neighborhood. Elevated living starts here. LIVE BOULDER, LOVE BOULDER!
New construction
$10,000,000
3633 21st St, Boulder, CO 80304
7beds
6,988sqft
Single Family Residence
Built in 2024
0.81 Acres Lot
$9,324,700 Zestimate®
$1,431/sqft
$-- HOA
What's special
Spa-inspired bathPrivate deck accessLush backyard oasisFire pitMedia roomTop-of-the-line thermador appliancesCustom cabinetry
- 152 days |
- 652 |
- 39 |
Zillow last checked:
Listing updated:
Listed by:
Marybeth Emerson 720-394-1997,
The Agency - Boulder
Source: IRES as distributed by MLS GRID,MLS#: 1051043
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Facts & features
Interior
Bedrooms & bathrooms
- Bedrooms: 7
- Bathrooms: 5
- Full bathrooms: 3
- 3/4 bathrooms: 1
- 1/2 bathrooms: 1
- Main level bathrooms: 1
Rooms
- Room types: Media Room
Primary bedroom
- Description: Carpet
- Features: Tub+Shower Primary, Luxury Features Primary Bath, 5 Piece Primary Bath
- Level: Upper
- Area: 416 Square Feet
- Dimensions: 16 x 26
Bedroom 2
- Description: Wood
- Level: Upper
- Area: 210 Square Feet
- Dimensions: 14 x 15
Bedroom 3
- Description: Wood
- Level: Upper
- Area: 195 Square Feet
- Dimensions: 13 x 15
Bedroom 4
- Description: Carpet
- Level: Upper
- Area: 242 Square Feet
- Dimensions: 11 x 22
Bedroom 5
- Description: Carpet
- Level: Upper
- Area: 195 Square Feet
- Dimensions: 13 x 15
Bedroom 6
- Description: Carpet
- Level: Lower
- Area: 168 Square Feet
- Dimensions: 12 x 14
Dining room
- Description: Wood
- Level: Main
- Area: 210 Square Feet
- Dimensions: 14 x 15
Kitchen
- Description: Wood
- Level: Main
- Area: 256 Square Feet
- Dimensions: 16 x 16
Laundry
- Description: Tile
- Level: Main
- Area: 140 Square Feet
- Dimensions: 10 x 14
Living room
- Description: Wood
- Level: Main
- Area: 702 Square Feet
- Dimensions: 26 x 27
Recreation room
- Description: Carpet
- Level: Lower
- Area: 630 Square Feet
- Dimensions: 18 x 35
Study
- Description: Wood
- Level: Main
- Area: 266 Square Feet
- Dimensions: 14 x 19
Heating
- Hot Water, Zoned, Radiant
Cooling
- Wall/Window Unit(s), Ceiling Fan(s)
Appliances
- Included: Gas Range, Dishwasher, Refrigerator, Washer, Dryer, Microwave, Disposal
Features
- Eat-in Kitchen, Separate Dining Room, Cathedral Ceiling(s), Open Floorplan, Pantry, Walk-In Closet(s), Kitchen Island
- Flooring: Wood
- Windows: Skylight(s), Wood Frames
- Basement: Full,Daylight
- Has fireplace: Yes
- Fireplace features: Gas
Interior area
- Total structure area: 4,798
- Total interior livable area: 6,988 sqft
- Finished area above ground: 4,798
Video & virtual tour
Property
Parking
- Total spaces: 3
- Parking features: Attached, Oversized
- Attached garage spaces: 3
- Details: Attached
Accessibility
- Accessibility features: Level Lot, Level Drive, Low Carpet
Features
- Levels: Tri-Level
- Patio & porch: Patio, Deck
- Exterior features: Sprinkler System
- Fencing: Partial,Security
- Has view: Yes
- View description: Hills
Lot
- Size: 0.81 Acres
- Features: Wooded, Evergreen Trees, Deciduous Trees, Level
Details
- Parcel number: R0004105
- Zoning: RES
- Special conditions: Private Owner
Construction
Type & style
- Home type: SingleFamily
- Architectural style: Contemporary
- Property subtype: Single Family Residence
Materials
- Frame
- Roof: Composition
Condition
- New construction: Yes
- Year built: 2024
Utilities & green energy
- Electric: XCEL
- Gas: XCEL
- Sewer: Public Sewer
- Water: City
- Utilities for property: Natural Gas Available, Electricity Available
Community & HOA
Community
- Security: Fire Sprinkler System, Fire Alarm
- Subdivision: 21st/Linden Sub
HOA
- Has HOA: No
Location
- Region: Boulder
Financial & listing details
- Price per square foot: $1,431/sqft
- Tax assessed value: $4,973,900
- Annual tax amount: $29,641
- Date on market: 2/6/2026
- Listing terms: Cash,Conventional
- Exclusions: Sellers personal property and any staging items
- Electric utility on property: Yes
Estimated market value
$9,324,700
$8.86M - $9.79M
$7,641/mo
Price history
| Date | Event | Price |
|---|---|---|
| 2/6/2026 | Listed for sale | $10,000,000-13%$1,431/sqft |
Source:  IRES as distributed by MLS GRID #1051043 Report a problem | ||
| 12/4/2025 | Listing removed | $11,500,000$1,646/sqft |
Source: IRES as distributed by MLS GRID #1031592 Report a problem | ||
| 4/18/2025 | Listed for sale | $11,500,000+155.6%$1,646/sqft |
Source: IRES as distributed by MLS GRID #1031592 Report a problem | ||
| 1/14/2022 | Sold | $4,500,000-9.1%$644/sqft |
Source: IRES as distributed by MLS GRID #952227 Report a problem | ||
| 10/18/2021 | Price change | $4,950,000-3.9%$708/sqft |
Source: IRES as distributed by MLS GRID #952227 Report a problem | ||
| 9/30/2021 | Listed for sale | $5,150,000+47.1%$737/sqft |
Source: IRES as distributed by MLS GRID #952227 Report a problem | ||
| 9/7/2017 | Sold | $3,500,000-6.7%$501/sqft |
Source: IRES as distributed by MLS GRID #828173 Report a problem | ||
| 8/7/2017 | Pending sale | $3,750,000$537/sqft |
Source: RE/MAX of Boulder, Inc #828173 Report a problem | ||
| 7/27/2017 | Price change | $3,750,000-6.1%$537/sqft |
Source: RE/MAX of Boulder, Inc #828173 Report a problem | ||
| 5/25/2017 | Listed for sale | $3,995,000+56.7%$572/sqft |
Source: RE/MAX of Boulder #3105735 Report a problem | ||
| 4/18/2014 | Sold | $2,550,000-7.3%$365/sqft |
Source: Public Record Report a problem | ||
| 1/28/2014 | Listed for sale | $2,750,000$394/sqft |
Source: Colorado Landmark, Realtors #726453 Report a problem | ||
| 9/12/2013 | Listing removed | $2,750,000$394/sqft |
Source: Colorado Landmark, Realtors #1223799 Report a problem | ||
| 8/22/2013 | Listed for sale | $2,750,000+58.5%$394/sqft |
Source: Colorado Landmark, Realtors (Boulder) #9999999 Report a problem | ||
| 6/3/2011 | Sold | $1,735,000-4.9%$248/sqft |
Source: Public Record Report a problem | ||
| 3/8/2011 | Price change | $1,825,000-8.7%$261/sqft |
Source: RE/MAX of Boulder #630421 Report a problem | ||
| 6/5/2010 | Listed for sale | $1,999,500-21.3%$286/sqft |
Source: RE/MAX of Boulder #630421 Report a problem | ||
| 10/24/2009 | Listing removed | $2,540,000$363/sqft |
Source: Colorado Landmark, Realtors #604752 Report a problem | ||
| 10/3/2009 | Price change | $2,540,000-5.6%$363/sqft |
Source: Colorado Landmark, Realtors #604752 Report a problem | ||
| 7/18/2009 | Listed for sale | $2,690,000$385/sqft |
Source: Colorado Landmark, Realtors #604752 Report a problem | ||
Public tax history
| Year | Property taxes | Tax assessment |
|---|---|---|
| 2025 | $29,936 +2.8% | $310,869 -9.7% |
| 2024 | $29,119 +27% | $344,313 +0% |
| 2023 | $22,935 +4.9% | $344,183 +39.4% |
| 2022 | $21,870 -2.4% | $246,976 -2.8% |
| 2021 | $22,405 | $254,083 -1.3% |
| 2020 | $22,405 +22.6% | $257,401 |
| 2019 | $18,273 | $257,401 +22.1% |
| 2018 | $18,273 | $210,766 -9.5% |
| 2017 | $18,273 +10.5% | $233,013 +22% |
| 2016 | $16,537 +5.6% | $191,040 +45% |
| 2015 | $15,660 +41.3% | $131,783 |
| 2014 | $11,080 -7% | $131,783 |
| 2013 | $11,916 +0.9% | $131,783 -7.4% |
| 2012 | $11,811 -9.9% | $142,245 |
| 2011 | $13,111 +7.1% | -- |
| 2010 | $12,243 +30.2% | $162,220 -6.2% |
| 2009 | $9,400 +3.5% | $172,970 +17.7% |
| 2008 | $9,079 -3.3% | $146,900 |
| 2007 | $9,388 +3.9% | $146,900 |
| 2006 | $9,039 +21.5% | $146,900 |
| 2005 | $7,440 +0.7% | $146,900 +20.6% |
| 2004 | $7,388 +15.7% | $121,770 |
| 2003 | $6,386 | $121,770 -87.5% |
| 2001 | -- | $976,200 |
Find assessor info on the county website
Monthly payment
Est. payment$--/mo
Payment breakdown
Explore the cost of this home by adjusting the details. Changes won't be saved.All calculations are estimates and provided by Zillow, Inc. for informational purposes only. Actual amounts may vary.
HOA fees may include property taxes on listings classified as Co-Ops. Contact the listing agent and/or owner for fee details.
Mortgage interest rates are dependent on a number of factors, including credit score, down payment, and repayment length. Interest rate data provided by Zillow Group Marketplace, Inc. as of 1/1/1970 from various mortgage lenders with which we have lead or other similar arrangements; the Estimated Payment is an average of those rates.
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Climate risks
Neighborhood: Carolyn Heights
Nearby schools
GreatSchools rating
- 4/10Columbine Elementary SchoolGrades: PK-5Distance: 0.7 mi
- 7/10Centennial Middle SchoolGrades: 6-8Distance: 0.3 mi
- 10/10Boulder High SchoolGrades: 9-12Distance: 2 mi
Schools provided by the listing agent
- Elementary: Columbine
- Middle: Centennial
- High: Boulder
Source: IRES as distributed by MLS GRID. This data may not be complete. We recommend contacting the local school district to confirm school assignments for this home.
A local agent can set up tours, give advice and negotiate with sellers.
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