The modular zone system is comprised of three modules: Use, Form, and Intensity. Combining elements of the three modules creates a zoning district. The zoning districts are identified in Section 9-5-2, "Zoning Districts," B.R.C. 1981.

(a)

Use Chart: The use chart establishes the uses that are permitted, conditionally permitted pursuant to Section 9-2-2, "Administrative Review Procedures," B.R.C. 1981, prohibited, or that may be permitted through use review pursuant to Section 9-2-15, "Use Review," B.R.C. 1981.

(b)

Form Chart: The form chart establishes the physical parameters for development, such as setbacks, building coverage, height, and special building design characteristics.

(c)

Intensity Chart: The intensity chart establishes the density at which development may occur and includes: minimum lot sizes, minimum open space per dwelling unit, number of dwelling units per acre, minimum open space per lot or parcel, and floor area ratios when applicable.

(a)

Classification: Zoning districts are classified according to the following classifications based on the predominant character of development and current or intended use in an area of the community:

(1)

R: Residential;

(2)

M: Mixed Use, a mix of residential and business;

(3)

B: Business;

(4)

DT: Downtown business zones;

(5)

I: Industrial;

(6)

P: Public;

(7)

A: Agricultural.

(b)

Zoning Districts: Under the classifications defined in Subsection (a) of this section, the particular zoning districts established for the city are as in table 5-1 of this section:

TABLE 5-1: ZONING DISTRICTS

(c)

Zoning District Purposes:

(1)

Residential Districts and Complementary Uses:

(A)

Residential - Rural 1, Residential - Rural 2, Residential - Estate, and Residential - Low 1: Primarily detached dwelling units with some duplexes and attached dwelling units at low to very low residential densities.

(B)

Residential - Low 2, and Residential - Medium 2: Medium density residential areas primarily used for small-lot residential development, including without limitation, duplexes, triplexes, or townhouses, where each unit generally has direct access at ground level.

(C)

Residential - Medium 1, and Residential - Medium 3: Medium density residential areas which have been or are to be primarily used for attached residential development, where each unit generally has direct access to ground level, and where complementary uses may be permitted under certain conditions.

(D)

Residential - Mixed 1: Mixed density residential areas with a variety of detached dwelling units, duplexes, and multi-unit dwellings that will be maintained; and where existing structures may be renovated or rehabilitated.

(E)

Residential - Mixed 2: Medium density residential areas which have a mix of densities from low density to high density and where complementary uses may be permitted.

(F)

Residential - High 1, Residential - High 2, Residential - High 4, Residential - High 5: High density residential areas primarily used for a variety of types of attached residential units, including without limitation, apartment buildings, and where complementary uses may be allowed.

(G)

Residential - High 3: High density residential areas in the process of changing to high density residential uses and limited pedestrian-oriented neighborhood-serving retail uses in close proximity to either a primary destination or a transit center and where complementary uses may be allowed.

(H)

Residential - High 6: High density residential urban areas that are predominantly townhouses in close proximity to either a primary destination or a transit center and where complementary uses may be allowed.

(I)

Residential - High 7: High density residential areas that have a fine grain of residential streets either existing or as part of a right-of-way plan approved by the city council and limited pedestrian-oriented neighborhood-serving retail uses in close proximity to either a primary destination or a transit center and where complementary uses may be allowed.

(J)

Mobile Home: Mobile home parks primarily used and developed at a medium residential density where complementary uses may be allowed under certain conditions.

(2)

Mixed Use Districts:

(A)

Mixed Use - 1: Mixed use areas which are primarily intended to have a mix of residential and nonresidential land uses within close proximity to each other and where complementary business uses may be permitted.

(B)

Mixed Use - 2: Mixed use residential areas adjacent to a redeveloping main street area, which are intended to provide a transition between a main street commercial area and established residential districts. Residential areas are intended to develop in a pedestrian-oriented pattern, with buildings built up to the street; with residential, office, and limited retail uses; and where complementary uses may be allowed.

(C)

Mixed Use - 3: Areas of the community that are changing to a mixture of residential and complementary nonresidential uses, generally within the same building.

(D)

Mixed Use - 4: Mixed use residential areas generally intended for residential uses with neighborhood-serving retail and office uses; and where complementary uses may be allowed. It is anticipated that development will occur in a pedestrian-oriented pattern, with buildings built up to the street.

(3)

Business Districts:

(A)

Business - Transitional 1 and Business - Transitional 2: Transitional business areas which generally buffer a residential area from a major street and are primarily used for commercial and complementary residential uses, including without limitation, temporary lodging and office uses.

(B)

Business - Main Street: Business areas generally anchored around a main street that are intended to serve the surrounding residential neighborhoods. It is anticipated that development will occur in a pedestrian-oriented pattern, with buildings built up to the street; retail uses on the first floor; residential and office uses above the first floor; and where complementary uses may be allowed.

(C)

Business - Community 1 and Business - Community 2: Business areas containing retail centers serving a number of neighborhoods, where retail-type stores predominate.

(D)

Business - Commercial Services: Commercial areas primarily used to provide to the community a wide range of retail and commercial uses including repair, service, and small-scale manufacturing uses and where complementary uses may be allowed.

(E)

Business - Regional 1 and Business - Regional 2: Business centers of the Boulder Valley, containing a wide range of retail and commercial operations, including the largest regional-scale businesses, which serve outlying residential development.

(4)

Downtown Districts:

(A)

Downtown - 1, Downtown - 2, and Downtown - 3: A transition area between the downtown and the surrounding residential areas where a wide range of retail, office, residential, and public uses are permitted. A balance of new development with the maintenance and renovation of existing buildings is anticipated, and where development and redevelopment consistent with the established historic and urban design character is encouraged.

(B)

Downtown - 4: The regional business area of the Boulder Valley known as the Central Business District which includes the downtown mall, where a wide range of retail, office, residential, and public uses are permitted and in which many structures may be renovated or rehabilitated. A balance of new development with the maintenance and renovation of existing buildings is anticipated, and where development and redevelopment consistent with the established historic and urban design character is encouraged.

(C)

Downtown - 5: The business area within the downtown core that is in the process of changing to a higher intensity use where a wide range of office, retail, residential, and public uses are permitted. This area has the greatest potential for new development and redevelopment within the downtown core.

(5)

Industrial Districts:

(A)

Industrial - Service 1 and Industrial - Service 2: Service industrial areas primarily used to provide to the community a wide range of repair and service uses and small-scale manufacturing uses.

(B)

Industrial - General: General industrial areas where a wide range of light industrial uses, including research and development, manufacturing, service industrial uses, media production, storage, and other intensive employment uses are located. Residential uses and other complementary uses may be allowed in appropriate locations.

(C)

Industrial - Manufacturing: Industrial manufacturing areas primarily used for more intensive manufacturing, research and development, service industrial uses, storage, and warehousing in buildings on large lots. Residential uses and other complementary uses may be allowed in appropriate locations.

(D)

Industrial - Mixed Services: Industrial areas on the edge of a main street commercial area, which are intended to provide a transition between a main street commercial area and established industrial zones. Industrial main street areas are intended to develop in a pedestrian-oriented pattern, with buildings built up to the street; first floor uses are predominantly industrial in character; uses above the first floor may include industrial, residential, or limited office uses, and where complementary uses may be allowed.

(6)

Public Districts:

(A)

Public: Public areas in which public and semi-public facilities and uses are located, including without limitation, governmental and educational uses.

(7)

Agricultural Districts:

(A)

Agricultural: Agricultural areas in a natural state or in which the growing of crops, flowers, and trees or other farming activity is practiced.

(8)

Flex Districts: A combination of use, form, and intensity standards not reflected in any existing zoning district. Rezoning to a flex district may only be initiated by the planning board or city council as part of an annexation, rezoning after concept review, or area plan, and upon the determination that the flex zone would implement the goals of the Boulder Valley Comprehensive Plan. When rezoning to a flex district, the rezoning ordinance shall identify the specific use, form, and intensity modules which shall be identified on the official zoning map. Nothing in this section shall be construed to prevent city council from creating new zoning districts.

Ordinance Nos. 7484 (2006); 7522 (2007); 7571 (2007); 7655 (2009); 7887 (2013); 8556 (2023); 8599 (2024); 8620 (2024); 8651 (2025); 8697 (2025)

(a)

The boundaries of the zoning districts defined in Section 9-5-2, "Zoning Districts," B.R.C. 1981, are set forth on a map entitled "Zoning District Map of the City of Boulder, Colorado" and adopted as part of this section. This map shall be kept in the city planning department and maintained as provided in Subsection (c) of this section.

(b)

Unless otherwise expressly defined on the zoning map, district boundary lines are lot lines, section lines, city limit lines, centerlines of stream beds, and centerlines of streets, alleys, or railroad rights of way, or such lines extended. District boundary lines shall be calculated on the northern and eastern edge of the zoning lines depicted on the zoning map. If uncertainty remains as to the boundary of a district after application of the provisions of this subsection, the planning board will interpret the district boundary.

(c)

All amendments to the zoning map shall be made by ordinance. The city manager shall, within a reasonable time after adoption of any such amendment, place the amendment on the zoning map.

(d)

All amendments made to the zoning map shall bear the ordinance number of the amendment, followed by the effective date of enactment of the amending ordinance in parenthesis, and shall be signed by the city manager after placement of the amendment upon the zoning map.