Summary: Before most new buildings or structures can be used or occupied in Seattle, a Certificate of Occupancy (commonly known as a "C of O") must be obtained. This certificate indicates that the project complies with the regulations for occupancy and activity required by the Seattle Building Code (Section 109). Changes in occupancy classification are not generally permitted until the building official has issued a C of O. A C of O is not required on remodel projects where the occupancy classification is not changing or for R-3 occupancy (single family or duplex). A mixed use building (e.g., containing parking, offices, retail and residential uses) will have a C of O that indicates all these occupancies. Be aware that "use" for Land Use Code purposes is not the same thing as "occupancy" for the Building Code. A C of O is typically for an entire building, exterior and interior (called "shell and core"), and all occupanies proposed within the building (e.g., offices and retail). However assembly occupancies (e.g., theatres or restaurants) require separate Certificates. Tenant improvements do not require a C of O unless there is a change in occupancy per the Building Code.
Date Revised: 04/16/2003