HIP Tool: SEPA Categorical Exemptions

SEPA (State Environmental Protection Act) categorical exemptions remove projects below a set threshold number of units from SEPA review. Typically, developments of more than four dwelling units are subject to an environmental review process under SEPA; however, jurisdictions are allowed to adopt higher exemption thresholds for single family, multifamily and other project types.


A higher exemption threshold may spare developers the expense and time of the environmental review process for relatively smaller and simpler projects, which can then translate into lower housing costs. The exemption threshold is variable and should be set to the level that achieves the most public benefit for an individual jurisdiction. See WAC 197-11-800 for the maximum exemption levels by project type.

To implement this tool, jurisdictional SEPA rules need to be amended to specify a higher threshold. Several central Puget Sound jurisdictions have raised the threshold to help spur new development.

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

  • Affordability