Exhibit 3.5

                            CERTIFICATE OF FORMATION

                                       OF

                               BROAN MFG. CO. LLC

      This Certificate of Formation of Broan Mfg. Co. LLC (the "LLC"), dated
March 9, 1999, is being duly executed and filed by Michael J. Sharon, as an
authorized person, to form a limited liability company under the Delaware
Limited Liability Company Act.

      FIRST: The name of the limited liability company formed hereby is Broan
Mfg. Co. LLC.

      SECOND: The address of the registered office of the LLC in the State of
Delaware is c/o The Prentice-Hall Corporation System, Inc., 1013 Centre Road,
Wilmington, New Castle County, Delaware 19805.

      THIRD: The name and address of the registered agent for service of process
on the LLC in the State of Delaware is The Prentice-Hall Corporation System,
Inc., 1013 Centre Road, Wilmington, New Castle County, Delaware 19805.

      FOURTH: The effective date of this certificate shall be April 4, 1999.

      IN WITNESS WHEREOF, the undersigned has executed this Certificate of
Formation as of the date first above written.

                                    /s/ Michael J. Sharon
                                  ----------------------------
                                  Michael J. Sharon, Authorized Person



                      AMENDMENT TO CERTIFICATE OF FORMATION

                                       OF

                               BROAN MGF. CO. LLC

      This Amendment to Certificate of Formation of Broan Mfg. Co. LLC, dated
March 19, 1999, is being duly executed and filed by Michael J. Sharon, as an
authorized person.

      The first article of the Certificate of Formation is hereby amended to
read in its entirety as follows:

      FIRST: The name of the limited liability company formed hereby is Broan
LLC.

      IN WITNESS WHEREOF, the undersigned has executed this Amendment to
Certificate of Formation as of the date first above written.

                                     /s/ Michael J. Sharon
                                    -------------------------------
                                    Michael J. Sharon, Authorized Person

                                      -2-


                   CERTIFICATE OF MERGER OF MJSRGC, INC. INTO
         BROAN LLC UNDER SECTION 18-209 OF THE LIMITED LIABILITY COMPANY
                          ACT OF THE STATE OF DELAWARE

      Pursuant to Section 18-209 of the Limited Liability Company Act of the
State of Delaware, Broan LLC, a Delaware limited liability company (the
"Company"), hereby certifies to the following information relating to the merger
of MJSRGC, Inc., a Delaware corporation (the "Disappearing Corporation"), with
and into the Company (the "Merger").

            1.    The respective names and states of incorporation or formation
                  of the company and the Disappearing Corporation, which are the
                  constituent entities in the Merger (the "Constituent
                  Corporations"), are:

                  Broan LLC               Delaware
                  MJSRGC, Inc.            Delaware

            2.    An agreement of merger between the Company and the
                  Disappearing Corporation (the "Merger Agreement") has been
                  approved and executed by each of the Constituent Corporations.

            3.    The Company is the surviving corporation to the Merger (the
                  "Surviving Corporation").

            4.    The name of the Surviving Corporation is Broan LLC.

            5.    The effective date of the Merger shall be April 4, 1999.

            6.    An executed copy of the agreement of merger is on file at the
                  principal place of business of the Surviving Corporation,
                  which is located at 926 West State Street, Hartford,
                  Wisconsin.

            7.    A copy of the agreement of merger will be furnished by the
                  Surviving Corporation, on request and without cost, to any
                  stockholder of any of the Constituent Corporations.

      IN WITNESS WHEREOF, this Certificate of Merger has been executed as of
this 31st day of March, 1999.

                                      BROAN LLC

                                      By:   /s/ Richard J. Harris
                                          -------------------------
                                      Its: Vice President
                                           Richard J. Harris

                                      -3-


                      AMENDMENT TO CERTIFICATE OF FORMATION

                                       OF

                                    BROAN LLC

      This Amendment to Certificate of Formation of Broan LLC ("Broan"), dated
September 17, 1999, is being duly executed and filed by Richard L. Bready, as
President of Nortek, Inc., the sole Member of Broan.

      The first article of the Certificate of Formation is hereby amended to
read in its entirety as follows:

      FIRST: The name of the limited liability company formed hereby is
Broan-NuTone LLC.

      IN WITNESS WHEREOF, the undersigned has executed this Amendment to
Certificate of Formation as of the date first above written.

                                       NORTEK, INC.

                                       By:  /s/ Richard L. Bready
                                           -------------------------
                                       Name: Richard L. Bready
                                       Its: President

                                      -4-