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Annex Flats Apartments

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(720) 706-2231
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1603 Walnut St, Boulder, CO 80302

Contact

Annex Flats

1603 Walnut St
Boulder, CO 80302
(720) 706-2231
Annex Flats in Boulder, CO - Building Photo
  • Studio–1 Bedrooms
  • $787-$1,968 Plus Fees
    12 Month Lease Term

About Annex Flats

Brand new Apartment building near downtown Boulder opening the end of September 2026 starting applications soon! Cafe and bakery on the ground floor and amazing event center on the rooftop for weddings, corporate and other events for rent. Residents will have a limited access to part of the roof top during non-event days with an amazing view of the flatirons. This is a Affordable community for people at the 30%-70% income levels in Boulder. Must income qualify. We have 1 bedroom and studio units. We are not student housing and if you are a full-time student you must meet the following requirements in order to eligible: A student who receives TANF A student who was previously in foster care program A student enrolled in a job training program and receives assistants under the Job Training Partnership Act A student who is a single parent.

Annex Flats is located in the Downtown Boulder Neighborhood and 80302 Zip code of Boulder, CO. This community is professionally managed by Brothers Property Management, Inc.

Property Contact Info

Office Hours

Monday8:30 am–12:00 pm
Tuesday8:30 am–12:00 pm
Wednesday8:30 am–12:00 pm
Thursday8:30 am–12:00 pm
FridayClosed
SaturdayClosed
SundayClosed

Floorplan Pricing and Availability

Annex Flats offers Studio to 1 Bedroom starting from $787. Here is the current pricing and availability:

  • Studio

    Floorplan 0bd

    From $787

    Studio, 1 Bath
    Plus Fees
    Available Now

    Availability Details

    PriceAvailability DateUnit
    From $787Available Now0bd

    Model Amenities and Features

    Features

    • Air Conditioning
    • Cable Ready
    • Handrails
    • Heating
    • Security System
    • Smoke Detector
    • Sprinkler System
    • Storage Space
    • Tenant Controlled HVAC
    • Tub/Shower
    • Wheelchair Accessible (Rooms)

    Kitchen

    • Dishwasher
    • Disposal
    • Freezer
    • Gas Range
    • Kitchen
    • Oven
    • Range
    • Refrigerator

    Model Lease Information

    Model Price Range

    • $787 - $1,968
  • 1 Bedroom

    Floorplan 1bd

    From $843

    1 Bed, 1 Bath
    Plus Fees
    Available Now

    Availability Details

    PriceAvailability DateUnit
    From $843Available Now1bd

    Model Amenities and Features

    Features

    • Air Conditioning
    • Cable Ready
    • Handrails
    • Heating
    • Security System
    • Smoke Detector
    • Sprinkler System
    • Storage Space
    • Tenant Controlled HVAC
    • Tub/Shower
    • Wheelchair Accessible (Rooms)

    Kitchen

    • Dishwasher
    • Disposal
    • Freezer
    • Gas Range
    • Kitchen
    • Oven
    • Range
    • Refrigerator

    Model Lease Information

    Model Price Range

    • $843 - $1,968
Price shown is base rent. Excludes user-selected optional fees and variable or usage-based fees and required charges due at or prior to move-in or at move-out. View Fees and Policies for details. Price, availability, fees, and any applicable rent special are subject to change without notice.

Schedule a Tour

Schedule a Tour
Call us at: (720) 706-2231 to schedule a tour.

Property Information

  • 30 Units
  • 4 Stories
  • Built in 2026

Income Restrictions At Annex Flats

Income restrictions apply to some or all residents. Contact the community for more information.

# Persons70% Income Limit 50% Income Limit 30% Income Limit
1$73,500$52,500$31,500
2$84,000$60,000$36,000
3$94,500$67,500$40,500
income restriction

To qualify, you must be equal to or below those in the chart, based on the number of persons living in the dwelling.

Lease Terms

  • 12 mo

Fees and Policies

The fees listed below are community-provided and may exclude utilities or add-ons. All payments are made directly to the property and are non-refundable unless otherwise specified.

Required Fees

One-Time Basics

Due at Application
Application FeeiCharged per unit.$28.00

Other Fees and Policies

Personal Add-Ons

Monthly Pet FeeiCharged Per Unit.$35.00/mo

Pet Fees

Cat
Pet DepositiCharged Per Unit.$300.00
Pet interview, Spayed/Neutered
Dog
Pet DepositiMax of 2. Charged Per Pet.$300.00
Monthly Pet FeeiCharged Per Unit.$35.00/mo
Pet interview, Spayed/Neutered, 30 lbs. Weight Limit
Comments:

Max of 2.

Storage Fees

Storage Small
Storage FeeiCharged Per Rentable Item.$30.00/mo
Storage Medium
Storage FeeiCharged Per Rentable Item.$40.00/mo
Storage Large
Storage FeeiCharged Per Rentable Item.$50.00/mo

Property Fee Disclaimer: Based on community-supplied data and independent market research. Subject to change without notice. May exclude fees for mandatory or optional services and usage-based utilities.

Features and Amenities

On-Site Services

  • On Site Retail
  • 24 Hour Access
  • Key Fob Entry
  • Laundry Facilities

Community Features

  • Elevator

Outdoor Features

  • Roof Terrace
  • Courtyard
  • Controlled Access

Interior Features

  • Tenant Controlled Hvac
  • Smoke Detector
  • Storage Space
  • Security System
  • Sprinkler System
  • Tub/Shower
  • Heating
  • Handrails
  • Cable Ready
  • Air Conditioning
  • Wheelchair Accessible (Rooms)

Kitchen Amenities

  • Gas Range
  • Dishwasher
  • Range
  • Refrigerator
  • Oven
  • Disposal
  • Freezer
  • Kitchen
Google Map

Map

1603 Walnut St, Boulder, CO 80302

Frequently Asked Questions about Annex Flats

Where is Annex Flats located?

Annex Flats is located at 1603 Walnut St near the Downtown Boulder area of Boulder, CO

What is the current rent range at Annex Flats?

Studio to 1 Bedroom Apartments at Annex Flats currently range from $787 to $1,968

When is the leasing office open?

  • The office Hours for Annex Flats are
  • Monday 8:30 am–12:00 pm
  • Tuesday 8:30 am–12:00 pm
  • Wednesday 8:30 am–12:00 pm
  • Thursday 8:30 am–12:00 pm
  • Friday Closed
  • Saturday Closed
  • Sunday Closed

Are pets allowed?

Call us today to find out our pet policy and if we allow pets

About Portable Tenant Screening Reports:

Applicant has the right to provide the property manager or owner with a Portable Tenant Screening Report (PTSR) that is not more than 30 days old, as defined in § 38-12-902(2.5), Colorado Revised Statutes; and 2) if Applicant provides the property manager or owner with a PTSR, the property manager or owner is prohibited from: a) charging Applicant a rental application fee; or b) charging Applicant a fee for the property manager or owner to access or use the PTSR.

Lifestyle Ratings

  • Affordability Super Value4.0

    The Annex Flats Apartments are 70.0% cheaper than the average apartment in the Downtown Boulder area, and 60.75% cheaper than the average apartment city-wide.

    Rent Comparison to the Downtown Boulder Neighborhood

    FloorplanLowest Price HereNeighborhood Avg RentNbhd Avg RentCost Difference%
    Studio$787$2,384-$1,597-67.0%
    1 Bedroom$843$3,117-$2,274-73.0%

    Rent Comparison to the city of Boulder

    FloorplanLowest Price HereCity Average RentCost Difference%
    Studio$787$2,011-$1,224-60.9%
    1 Bedroom$843$2,142-$1,299-60.6%

    Methodology: On 07/19/2026, ApartmentHomeLiving.com compared current rents by floorplan to 43 other apartment communities in the immediate area around Annex Flats (Downtown Boulder), and 436 other apartment communities in Boulder using today’s up-to-date pricing using the sum/count averaging formula. This data will be updated in real-time as prices fluctuate.

    Rent Pricing Data as of 07/19/2026

Learn more about Lifestyle Search

Nearby Schools

Whittier Elementary School

Boulder Valley Re 2 School District
2008 Pine Street
Public School - Grades K-5 (269 Students)
In Attendance Zone1 minute drive / 0.4 miles away
8/10

Boulder High School

Boulder Valley Re 2 School District
1604 Arapahoe Avenue
Public School - Grades 9-12 (2074 Students)
In Attendance Zone1 minute drive / 0.3 miles away
10/10
School data provided by GreatSchools.
details
The GreatSchools Rating helps parents compare schools within a state based on a variety of school quality indicators and provides a helpful picture of how effectively each school serves all of its students. Ratings are on scale of 1 (below average) and to 10 (above average) and can include test scores, college readiness, academic progress, advanced courses, equity, discipline and attendance data. We also advise parents to visit schools, consider other information on school performance and programs, and consider needs as part of the school selection process.

About GreatSchools Data on ApartmentHomeLiving.com.

Points of Interest

Time and distance from Annex Flats.

Big Box and Retail

Target

2800 Pearl St
2 minute drive / 0.75 miles away

Walgreens

2870 28th St
2 minute drive / 0.87 miles away

Costco

600 Marshall Rd
14 minute drive / 6.56 miles away

Colleges and Universities

Naropa University - Arapahoe Campus

2130 Arapahoe Ave
1 minute drive / 0.37 miles away

University of Colorado at Boulder

2055 Regent Drive
3 minute drive / 1.0 miles away

University of Colorado at Boulder - East Campus

Regent Drive at Broadway
4 minute drive / 1.37 miles away

Groceries

Trader Joe's

1906 28th St
1 minute drive / 0.65 miles away

King Soopers

2900 Arapahoe Rd
19 minute drive / 9.02 miles away

Hospitals

Boulder Community Health

4747 Arapahoe Avenue
5 minute drive / 1.82 miles away

Centura Health - Avista Adventist Hospital

100 Health Park Dr
17 minute drive / 7.98 miles away

Centennial Peaks Hospital

2255 S 88th St
17 minute drive / 8.03 miles away

Shopping Centers

Folsom Village

1605-1665 Folsom St
1 minute drive / 0.46 miles away

The Village

2525 Arapahoe Ave
1 minute drive / 0.51 miles away

Pearl Street Plaza

2600-2710 Pearl St
1 minute drive / 0.53 miles away

Annex Flats has 5 shopping centers within 0.6 miles.

Nearby Neighborhoods

Pearl Street Mall

Studio to 5 Bedroom Apartments from $1,550
View Rentals

Central Boulder

Studio to 5 Bedroom Apartments from $1,550
View Rentals

Whittier Boulder

Studio to 5 Bedroom Apartments from $1,550
View Rentals

Rental Price Ranges in the Area

BedroomAverage RentCheapest RentHighest Rent
Boulder Studio Apartments $2,011$787$3,068
Boulder 1 Bedroom Apartments $2,142$843$4,205
Boulder 2 Bedroom Apartments $2,447$800$5,247
Boulder 3 Bedroom Apartments $3,119$1,305$6,891
Boulder 4 Bedroom Apartments $2,406$1,570$6,305

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Viewing: Annex Flats | Desktop Version | Listing Updated: 07/18/2026 | AHLSLV