<PAGE>
                                                                   Exhibit 10.19


NORTEK

RICHARD L. BREADY
Chairman and CEO


October 31, 2003


John Forbis
President and CEO
Kroy Building Products, Inc.
2719 N. Division Avenue
P.O. Box 636
York, NE  68467

Dear John,

     This letter describes the terms and conditions of the key employee
incentive program for the possible sale of Ply Gem Industries, Inc., including
its wholly-owned subsidiaries Variform, Inc., Napco, Inc., Great Lakes Window,
Inc., Kroy Buildings Products, Inc. and Thermal-Gard, Inc., and the business of
the CWD Windows and Doors Division of Broan-NuTone Canada Inc. (collectively
"WDS").

     1. Upon the closing of the sale of WDS, you will be paid by Nortek,
        Inc. a cash incentive bonus of $400,000, payable on or before the 10th
        day after Nortek receives payment from the sale.

     2. Upon the closing of the sale of WDS:  (a) the Class A Options previously
        granted to you pursuant to the Nortek Holdings, Inc. 2002 Stock Option
        Plan shall become fully vested; and (b) the Class A and Class B Options
        previously granted to you shall remain exercisable by you (subject to
        all other conditions of the Plan, including the requirements that a
        minimum Exit Value per share in excess of $92 is achieved and that the
        Kelso entities achieve the 17% Investor Return) regardless of your
        continued employment with WDS after the sale.  A copy of the resolution
        of the Compensation Committee of the Nortek Holdings Board of Directors
        is enclosed together with a copy of the Stock Option Plan.

     3. No payments or arrangements pursuant to paragraphs 1 and 2 above shall
        be made if you are not employed by WDS (for any reason) on the sale date
        or you have not committed the necessary time and effort toward the sale
        of WDS which shall include preparing due diligence materials, preparing
        presentation material, meeting with potential buyers and otherwise
        acting in the best interests of the shareholders of WDS.


      NORTEK, INC., 50 KENNEDY PLAZA, PROVIDENCE, RHODE ISLAND 02903-2360
                         401-751-1600  FAX 401-751-4610
<PAGE>

                                                                               2

     4. In the event the sale of WDS is not completed on or before March 31,
        2004, this letter shall be null, void and have no further affect and any
        obligation or agreement set forth herein shall immediately terminate
        even if WDS is sold at some later date.

     5. This letter should in no way be viewed as any guarantee of continued
        employment with WDS.

     6. All payments shall be subject to any applicable withholdings and any tax
        on such amounts shall be your responsibility.  It is understood that
        payments made pursuant to this letter do not create any employment
        arrangement between any individual and Ply Gem, Nortek or any Nortek
        subsidiary.  Any payments made pursuant to this agreement are not
        counted toward any pension, 401(k) or other benefit plan of WDS or
        Nortek.

     7. This letter sets forth the entire understanding regarding what payment,
        if any, shall be made to you upon the sale of WDS except as may be set
        forth in a written agreement between the parties or contained in written
        benefit plans available to employees or executives generally.

                                                 Very truly yours,


                                                  Richard L. Bready






      NORTEK, INC., 50 KENNEDY PLAZA, PROVIDENCE, RHODE ISLAND 02903-2360
                         401-751-1600  FAX 401-751-4610