Zoning for Affordable Housing

One of the core values of the Boulder Valley Comprehensive Plan is a commitment to “a diversity of housing types and price ranges.” There are many standards in Boulder’s land use code that determine the type, size, and number of housing units that can be built, particularly the code’s “intensity standards” (minimum lot area, minimum open space, maximum floor area ratio) as well as the parking requirements for housing. This project considered updates to those standards that may create barriers to the development of smaller, more easily attainable housing.

On Oct. 5, City Council adopted an ordinance that changes the Land Use Code that removes barriers in order to allow more housing units in some areas, enable smaller homes and encourage a greater diversity of housing types. This includes allowing more housing units in growth areas like the Boulder Valley Regional Center, neighborhood centers and industrial areas as well as allowing duplexes and triplexes in low density residential areas if they are consistent with current density limits.

The adopted changes go into effect on Jan. 1, 2024.

Questions or comments?
Email Karl Guiler, Senior Policy Advisor.

The zoning changes affect the review process for larger development projects, or the Site Review process, as well as density calculations, setbacks, parking and subdivision requirements, all meant to streamline regulations to encourage more middle housing types like duplexes, triplexes, quadplexes and townhouses, and more modest sized housing. Consistent with these goals, the city’s lowest density residential zones are now permitted to have duplexes and triplexes, but only if the current density requirements, two to six dwelling units per acre, are met.

Changes include:

• Review Process, Intensity, & Form and Bulk Standards
  • Site Review thresholds and process changes to encourage middle housing and more units. Staff considers duplexes, townhouses, three - and fourplexes middle housing.
    • Remove some of the Site Review thresholds based on number of dwelling units and replace with new square footage thresholds.
    • Eliminate the automatic Planning Board review requirement for requests for additional units and allow that density limit by-right (without mandatory Planning Board review) for the following zones: RH-1, RH-2, RH-3, and RH-7 (RH: Residential High zones).
    • Revise form and bulk standards to allow townhouses by-right at zero setback between townhouse units without having to go through Site Review.
• Use Standards
  • Housing use type allowances to get more middle housing and more units.
    • Allow duplexes and triplexes by-right in RL, RR and RE zones in the Use Table with no change to density (only allows additional units if minimum lot area per unit is met on a lot, e.g., 7,000 sq. ft. in RL-1, 7,500 sq. ft. in RE, and 30,000 sq. ft. in RR).
    • Eliminate Use Review requirement for efficiency living units (ELUs) (units that are 475 sq. ft. or smaller). Current requirement is that projects with 40% ELUs require Use Review. Site Review already requires a diversity of housing types.
• Intensity Standards
  • Revisions to density calculations to obtain more housing, including more deed restricted affordable housing.
    • Revise density calculation requirements to allow more housing and remove incentives to develop larger sized units. Replace lot area per dwelling unit and open space per dwelling calculations with a floor area ratio (FAR) limits for each of the following zones:
      • BR-1: 1,600 sq. ft. of lot area per dwelling unit removed, 2.0 FAR already set in code.
      • BC-1: 1,200 sq. ft. of open space per dwelling unit replaced with 1.5 FAR and 15% open space per lot requirement. Up to a 2.0 FAR permitted in areas mapped in Appendix N from the code.
      • BC-2: 1,600 sq. ft. lot area per dwelling unit replaced with 1.5 FAR and 15% open space per lot requirement. Up to a 2.0 FAR permitted in areas mapped in Appendix N from the code.
      • IG and IM: 1,600 sq. ft. lot area per dwelling unit and 600 square feet of open space per dwelling unit requirement to be replaced with 1.5 and 1.4 FAR respectively and a 30% open space per lot requirement for residential uses. A floor area increase up to 1.25 for residential uses is also proposed if at least 0.3 FAR of a lot or parcel is used for industrial or research and development uses.
      • BT-1: Similar to RH-4 below which is in the same intensity module, the 1,200 sq. ft. of open space per unit requirement would be replaced with a 1.0 FAR limit per lot and 30% open space per lot requirement. Up to a 1.4 FAR permitted with Site Review from a base 1.0 FAR.
      • BT-2: Removes the minimum lot area per dwelling unit requirement. Up to a 0.9 FAR permitted with Site Review from a base 0.5 FAR.
  • Revised density calculations in the Residential High (RH) zoning districts and removed incentives to develop larger sized units. Replaced density calculations for the following zones using open space to determine density with a FAR limit for each:
    • RH-1 and RH-2: Simplify the RH-1 and RH-2 zoning districts by:
      • Combine the zones into the same intensity module (see below) given the similar scale and context of the two zones;
      • Eliminate the 1,600 sq. ft. of open space requirement for RH-1 and 3,000 sq. ft. of lot area per unit requirement in RH-2 and replace both with a 0.67 FAR limit and 40% open space per lot requirement;
      • Eliminate the current requirements for floor area measurement in the RH-1 zone which are different from all other zones, and
      • Remove the 27 dwelling units per acre limit in the RH-2 zone.
      • Up to a 1.07 FAR permitted with Site Review from a base of 0.67 FAR.
  • RH-3: Modify to have a 30% open space per lot requirement, which is the current requirement if approved by Planning Board.
  • RH-4: Replace the 1,200 sq. ft. of open space per unit requirement with a 1.0 FAR limit per lot and 30% open space per lot requirement.
  • RH-5: Replace the 1,600 sq. ft. of lot area per unit with a 1.5 FAR limit per lot and 15% open space per lot requirement.
    • Notes:
      • Open space: Per existing code requirements, any developments with buildings over 45 feet must provide at least 20% open space on the site in all zones. This requirement is not proposed to change.
      • Occupancy: A change was made to Section 9-8-5(a), B.R.C. 1981 related to occupancy to maintain the intent of Ordinance 8585 to “freeze” nonconformities at the occupancy levels prior to the passage of the ordinance. This is proposed, because the density changes above will render some properties conforming. The change is focused on RH-2 and RH-5, which are the high-density residential zones nearest to the University Hill neighborhood. The changes above would not impact the nonconformities in the low density residential (i.e., RL-1) areas.
• Parking Standards
  • Relaxes some parking standards to remove potential barriers to construction of more housing units.
    • Eliminate the current parking requirement of 1.25 parking spaces for one bedroom units and applies a 1 space per unit standard.
    • Allow Residential Parking Reductions up to 25% through an Administrative Review (staff level) process, where currently all residential parking reductions require Site Review.
    • Update parking reduction criteria to have stronger Transportation Demand Management requirements.
    • Reorganize parking reduction criteria to be clearer and better organized by land use.
• Subdivision Standards
  • Modify subdivision requirements to allow more flexible lot standards for townhouse projects.
    • Allow the creation of townhouse lots to be less than the minimum width of 30 feet, down to 15 feet for lots that have one townhouse unit without any waivers to the subdivision requirements.