Subdivision Regulations

Subdivision regulations guide how land can be divided and designed into lots, blocks, and open space. As a foundational element in determining the character and quality of a community, subdivision regulations determine the process, pattern, and horizontal scale of development.

Subdivision regulations generally include the following components:

  • Procedural information: who participates in the process, how, and when
    • Development-type standards: clusters, PUDs, condominiums, tiny villages
    • Lot, block, open space, and easement standards
    • Transportation and public utility standards
    • Miscellaneous standards such as development phasing and covenants

As they relate to wildfire, subdivision regulations can reduce wildfire risk through neighborhood design, requirements for multiple access points for emergency response and evacuation, open space, easements, and adequate water infrastructure/access.

Regulations regarding development phasing, covenants (establishment of covenants and HOAs), and easement standards are often overlooked components of subdivision regulations that can impact wildfire risk. Development phasing determines the extent to which water infrastructure and transportation access levels must be completed before constructing the first proposed structure. Permissible covenants and HOA rules can inform more parcel-by-parcel wildfire mitigation measures such as landscaping, buffering, and gutter maintenance. Easements can be crucial for creating long-term, strategic fuel breaks for communities.

Many communities are unifying regulations that govern land development into one ordinance to reduce complexity for users and make it easier for communities to update one ordinance rather than multiple. A unified development ordinance could include regulations such as subdivision, zoning, open space, and other ancillary codes.

Community Examples

Missoula County, Montana – The Missoula County Subdivision Regulations include succinct, detailed requirements for reducing wildfire risk to structures. The standards apply to all subdivisions in Wildfire Hazard Areas. These standards include:

  • Fire chimneys
  • Defensible space, clearing and maintenance agreement
  • Fire suppression
  • Notification

Sample Language

Missoula County Subdivision Regulations | “An application for a proposed subdivision that contains a defined hazard within the subdivision boundaries, or is located adjacent, upstream or downstream to a hazard, when applicable, shall include the supplemental information described below….”“Wildfire Hazard Area Standards: Defensible space shall be created within 100 feet of all subdivision roads and water supplies and water facilities that are designated for fire suppression.”