MILLER BUILDING SYSTEMS, INC. EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT JUNE 27, 1998 The subsidiaries of the Registrant are as follows: Percentage of Voting Incorporated Securities Owned by Name Under Law of: Immediate Parent Miller Building Systems of Indiana, Inc. Indiana 100% Miller Building Systems of Pennsylvania,Inc. Indiana 100% Miller Building Systems of Kansas, Inc. Kansas 100% Miller Building Systems of South Dakota,Inc. South Dakota 100% (1) Miller Construction Services, Inc. Indiana 100% United Structures, Inc. New York 100% PME Pacific Systems, Inc. California 100% (2) (1) Wholly-owned subsidiary of Miller Building Systems of Kansas, Inc. (2) Inactive Corporation with no assets.