<PAGE>   1

                                  EXHIBIT 24.0
                               POWER OF ATTORNEY


     KNOW ALL MEN BY THESE PRESENTS, that each of the undersigned hereby
constitutes and appoints Richard O. Ballentine and John Huey, and each of
them, his true and lawful attorneys-in-fact and agents, with full power of
substitution and revocation in each, for him/her and in his/her name, place
and stead, to sign any or all reports (including reports on Form 10-K, Form 3,
Form 4, Form 5, Schedule 13-D, Schedule 13-G, and Form 144), and any
amendments thereto, required or permitted to be filed by him under the
Securities and Exchange Act of 1934, or the Securities Act of 1933, with
respect to beneficial ownership of, and transactions in, equity securities of
BUTLER MANUFACTURING COMPANY, a Delaware corporation (the "Company"), and with
respect to other matters relating to the Company, and to file the same, with
all documents required or permitted to be filed in connection therewith, with
the Securities and Exchange Commission, granting unto said attorneys-in-fact
and agents, and each of them, full power and authority to do and perform each
and every act and thing requisite and necessary to be done in and about the
premises as fully to all intents and purposes as he might or could do in
person, hereby ratifying and confirming all that said attorneys-in-fact and
agents, or any of them, or their substitute or substitutes, may lawfully do or
cause to be done by virtue hereof.


          DATED:        JANUARY 16, 1996  /S/ HAROLD G. BERNTHAL
                                          ---------------------------
                                              HAROLD G. BERNTHAL

          DATED:        JANUARY 12, 1996  /S/ ROBERT E. COOK
                                          ---------------------------
                                              ROBERT E. COOK

          DATED:        JANUARY 12, 1996  /S/ ALAN M. HALLENE
                                          ---------------------------
                                              ALAN M. HALLENE

          DATED:        JANUARY 10, 1996  /S/ C.L. WILLIAM HAW
                                          ---------------------------
                                              C.L. WILLIAM HAW

          DATED:        JANUARY 16, 1996  /S/ GEORGE E. POWELL, JR.
                                          ---------------------------
                                              GEORGE E. POWELL, JR.

          DATED:        JANUARY 15, 1996  /S/ DONALD H. PRATT.
                                          ---------------------------
                                              DONALD H. PRATT

          DATED:        JANUARY 10, 1996  /S/ ROBERT J. REINTJES, SR.
                                          ---------------------------
                                              ROBERT J. REINTJES, SR.

          DATED:        JANUARY 13, 1996  /S/ JUDITH A. ROGALA
                                          ---------------------------
                                              JUDITH A. ROGALA

          DATED:        JANUARY 9, 1996   /S/ ROBERT H. WEST
                                          ---------------------------
                                              ROBERT H. WEST