- Tip 257, Developer Contributions – Mandatory Housing Affordability, was updated to add information to the charts and to add a section about choosing to use the MHA codes.
- DR 2-2018, Determination of State Environmental Policy Act (SEPA) Review Exemption Levels for Infill Residential and Mixed-Use Development in Urban Centers, describes terms, processes, and limits on how exemption levels will be applied.
- DR 10-2018, Adjustment to the Amount of Emergency Relocation Assistance Payment Under the Housing and Building Maintenance Code, implements an annual adjustment of the amount of relocation assistance by the percentage amount of change in the housing component of the Consumer Price Index.
- DR 11-2018, Adjustment to the Amount of Relocation Assistance Payment Under the Tenant Relocation Assistance Ordinance, adjusts the amount of relocation assistance required in SMC Section 22.210.130.A. by the percentage amount of change in the Housing Component of the Consumer Price Index.
- DR 13-2018, Great Blue Heron Management, which supersedes DR 5-2007, establishes a 197-foot, year-round buffer around great blue heron nesting colonies. The rule also establishes seasonal buffers around nesting colonies.