HIP Tool: Minimum Densities

 Maximum densities are a key feature of zoning, but development may occur at intensities much lower than the intent of the zone (e.g., development occurs at four dwelling units/acre when maximum zoning allows for 10 DU/acre). Supplemental minimum densities can be used by jurisdictions to require more efficient use of available residential-zoned land.


Background

Development at a very low density can result in land use patterns that are difficult or more costly to serve with infrastructure and utilities, reducing affordability. Untapped development potential may be lost as it can be difficult for these areas to redevelop when there is more demand for housing, forcing development to sprawl. Enacting a minimum density ordinance can help ensure that housing is built at sufficient densities to support transit or provide a variety of housing choices.

Setting a “floor” for density within zones can ensure that development is consistent with comprehensive plan density goals. The minimum density may vary by zone or be a specified percentage of the maximum density. When calculating the minimum density allowed, jurisdictions should consider whether to calculate the density based on the net buildable area of a parcel or the gross land area.

Tool Profile

Focus Areas

  • Expensive Housing Markets
  • Innovative Single Family Techniques

Project Types

  • Single Family
  • Ownership
  • Market Rate

Affordability Level

  • 80 to 120% AMI
  • Less than 80% AMI

Housing Goal

  • Diversity