Summary: City of Seattle regulations for environmentally critical areas (ECAs) include a provision authorizing the Seattle Department of Construction and Inspections (SDCI) to allow a 25 percent reduction (up to a maximum of 5 feet) in yard or setback requirements for development on a lot in existence as a legal building site prior to Oct. 31, 1992. This reduction does not require a variance if the full width of a riparian management area, steep slope erosion hazard area buffer, or wetland buffer is maintained. ECA regulations are contained in the Seattle Municipal Code (SMC), Chapter 25.09.
Date Revised: 05/29/2025