The Seattle Building & Construction Trades Council has 19 Affiliated Local Unions, representing over 10,500 members in Seattle and King County.

The object of this Council is to construct a central organization which shall conserve the interests of all labor organizations engaged in the erection or alteration of buildings, for the purpose of assisting each other when necessary, thereby removing all unjust and injurious competition and to secure unity of action for their mutual protection and support of all members of Building Trades Unions.