Document:

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                                                                     EXHIBIT 4.5

Schedule to Huttig promissory note in favor of certain lenders.

Lender                                                     Principal sum

First Union National Bank                                  $15,000,000

The Dai-Ichi Kangyo Bank, Ltd.                             $10,000,000

The Bank of New York                                       $15,000,000

Mercantile Bank National Association                       $15,000,000<PAGE>   1
                                                                     Exhibit 4.6

                           CERTIFICATE OF DESIGNATIONS
                                       of

                  SERIES A JUNIOR PARTICIPATING PREFERRED STOCK
                                       of
                         HUTTIG BUILDING PRODUCTS, INC.

                         (Pursuant to Section 151 of the
                        Delaware General Corporation Law)

                -------------------------------------------------

                  Huttig Building Products, Inc., a corporation organized and
existing under the General Corporation Law of the State of Delaware (hereinafter
called the "Corporation"), hereby certifies that the following resolution was
adopted by the Board of Directors of the Corporation as required by Section 151
of the General Corporation Law at a meeting duly called and held on December 6,
1999:

                  RESOLVED, that pursuant to the authority granted to and vested
in the Board of Directors of this Corporation in accordance with the provisions
of the Restated Certificate of Incorporation of the Corporation, the Board of
Directors hereby creates a series of Preferred Stock, par value $.01 per share
(the "Preferred Stock"), of the Corporation and hereby states the designation
and number of shares, and fixes the relative rights, preferences, and
limitations thereof as follows:

                  Series A Junior Participating Preferred Stock:

                  Section 1. Designation and Amount. The shares of this series
shall be designated as "Series A Junior Participating Preferred Stock" (the
"Series A Preferred Stock") and the number of shares constituting the Series A
Preferred Stock shall be 250,000. Such number of shares may be increased or
decreased by resolution of the Board of Directors; provided, that no decrease
shall reduce the number of shares of Series A Preferred Stock to a number less
than the number of shares then outstanding plus the number of shares reserved
for issuance upon the exercise of outstanding options, rights or warrants or
upon the conversion of any outstanding securities issued by the Corporation
convertible into Series A Preferred Stock.

                  Section 2. Dividends and Distributions.

         (A) Subject to the rights of the holders of any shares of any series of
         Preferred Stock (or any other stock) ranking prior and superior to the
         Series A Preferred Stock with respect to dividends, the holders of
         shares of Series A Preferred Stock, in preference to the holders of
         Common Stock, par value $.01 per share (the "Common Stock"), of the
         Corporation, and of any other junior stock, shall be

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         entitled to receive, when, as and if declared by the Board of Directors
         out of funds legally available for the purpose, quarterly dividends
         payable in cash on the first day of March, June, September and December
         in each year (each such date being referred to herein as a "Quarterly
         Dividend Payment Date"), commencing on the first Quarterly Dividend
         Payment Date after the first issuance of a share or fraction of a share
         of Series A Preferred Stock, in an amount per share (rounded to the
         nearest cent) equal to the greater of (a) $1 or (b) subject to the
         provision for adjustment hereinafter set forth, 100 times the aggregate
         per share amount of all cash dividends, and 100 times the aggregate per
         share amount (payable in kind) of all non-cash dividends or other
         distributions, other than a dividend payable in shares of Common Stock
         or a subdivision of the outstanding shares of Common Stock (by
         reclassification or otherwise), declared on the Common Stock since the
         immediately preceding Quarterly Dividend Payment Date or, with respect
         to the first Quarterly Dividend Payment Date, since the first issuance
         of any share or fraction of a share of Series A Preferred Stock. In the
         event the Corporation shall at any time declare or pay any dividend on
         the Common Stock payable in shares of Common Stock, or effect a
         subdivision or combination or consolidation of the outstanding shares
         of Common Stock (by reclassification or otherwise than by payment of a
         dividend in shares of Common Stock) into a greater or lesser number of
         shares of Common Stock, then in each such case the amount to which
         holders of shares of Series A Preferred Stock were entitled immediately
         prior to such event under clause (b) of the preceding sentence shall be
         adjusted by multiplying such amount by a fraction, the numerator of
         which is the number of shares of Common Stock outstanding immediately
         after such event and the denominator of which is the number of shares
         of Common Stock that were outstanding immediately prior to such event.

         (B) The Corporation shall declare a dividend or distribution on the
         Series A Preferred Stock as provided in paragraph (A) of this Section
         immediately after it declares a dividend or distribution on the Common
         Stock (other than a dividend payable in shares of Common Stock);
         provided that, in the event no dividend or distribution shall have been
         declared on the Common Stock during the period between any Quarterly
         Dividend Payment Date and the next subsequent Quarterly Dividend
         Payment Date, a dividend of $1 per share on the Series A Preferred
         Stock shall nevertheless be payable on such subsequent Quarterly
         Dividend Payment Date.

         (C) Dividends shall begin to accrue and be cumulative on outstanding
         shares of Series A Preferred Stock from the Quarterly Dividend Payment
         Date next preceding the date of issue of such shares, unless the date
         of issue of such shares is prior to the record date for the first
         Quarterly Dividend Payment Date, in which case dividends on such shares
         shall begin to accrue from the date of issue of such shares, or unless
         the date of issue is a Quarterly Dividend Payment Date or is a
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         date after the record date for the determination of holders of shares
         of Series A Preferred Stock entitled to receive a quarterly dividend
         and before such Quarterly Dividend Payment Date, in either of which
         events such dividends shall begin to accrue and be cumulative from such
         Quarterly Dividend Payment Date. Accrued but unpaid dividends shall not
         bear interest. Dividends paid on the shares of Series A Preferred Stock
         in an amount less than the total amount of such dividends at the time
         accrued and payable on such shares shall be allocated pro rata on a
         share-by-share basis among all such shares at the time outstanding. The
         Board of Directors may fix a record date for the determination of
         holders of shares of Series A Preferred Stock entitled to receive
         payment of a dividend or distribution declared thereon, which record
         date shall be not more than 60 days prior to the date fixed for the
         payment thereof.

                  Section 3. Voting Rights. The holders of shares of Series A
Preferred Stock shall have the following voting rights:

         (A) Subject to the provision for adjustment hereinafter set forth, each
         share of Series A Preferred Stock shall entitle the holder thereof to
         100 votes on all matters submitted to a vote of the stockholders of the
         Corporation. In the event the Corporation shall at any time declare or
         pay any dividend on the Common Stock payable in shares of Common Stock,
         or effect a subdivision or combination or consolidation of the
         outstanding shares of Common Stock (by reclassification or otherwise
         than by payment of a dividend in shares of Common Stock) into a greater
         or lesser number of shares of Common Stock, then in each such case the
         number of votes per share to which holders of shares of Series A
         Preferred Stock were entitled immediately prior to such event shall be
         adjusted by multiplying such number by a fraction, the numerator of
         which is the number of shares of Common Stock outstanding immediately
         after such event and the denominator of which is the number of shares
         of Common Stock that were outstanding immediately prior to such event.

         (B) Except as otherwise provided herein, in any other Certificate of
         Designations creating a series of Preferred Stock or any similar stock,
         in the Restated Certificate of Incorporation of the Corporation or by
         law, the holders of shares of Series A Preferred Stock and the holders
         of shares of Common Stock and any other capital stock of the
         Corporation having general voting rights shall vote together as one
         class on all matters submitted to a vote of stockholders of the
         Corporation.

         (C) Except as set forth herein, or as otherwise provided by law,
         holders of Series A Preferred Stock shall have no special voting rights
         and their consent shall not be required (except to the extent they are
         entitled to vote with holders of Common Stock as set forth herein) for
         taking any corporate action.
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                  Section 4. Certain Restrictions.

         (A) Whenever quarterly dividends or other dividends or distributions
         payable on the Series A Preferred Stock as provided in Section 2 are in
         arrears, thereafter and until all accrued and unpaid dividends and
         distributions, whether or not declared, on shares of Series A Preferred
         Stock outstanding shall have been paid in full, the Corporation shall
         not:

                  (i) declare or pay dividends, or make any other distributions,
                  on any shares of stock ranking junior (either as to dividends
                  or upon liquidation, dissolution or winding up) to the Series
                  A Preferred Stock;

                  (ii) declare or pay dividends, or make any other
                  distributions, on any shares of stock ranking on a parity
                  (either as to dividends or upon liquidation, dissolution or
                  winding up) with the Series A Preferred Stock, except
                  dividends paid ratably on the Series A Preferred Stock and all
                  such parity stock on which dividends are payable or in arrears
                  in proportion to the total amounts to which the holders of all
                  such shares are then entitled;

                  (iii) redeem or purchase or otherwise acquire for
                  consideration shares of any stock ranking junior (either as to
                  dividends or upon liquidation, dissolution or winding up) to
                  the Series A Preferred Stock, provided that the Corporation
                  may at any time redeem, purchase or otherwise acquire shares
                  of any such junior stock in exchange for shares of any stock
                  of the Corporation ranking junior (as to dividends and upon
                  dissolution, liquidation or winding up) to the Series A
                  Preferred Stock; or

                  (iv) redeem or purchase or otherwise acquire for consideration
                  any shares of Series A Preferred Stock, or any shares of stock
                  ranking on a parity with the Series A Preferred Stock, except
                  in accordance with a purchase offer made in writing or by
                  publication (as determined by the Board of Directors) to all
                  holders of such shares upon such terms as the Board of
                  Directors, after consideration of the respective annual
                  dividend rates and other relative rights and preferences of
                  the respective series and classes, shall determine in good
                  faith will result in fair and equitable treatment among the
                  respective series or classes.
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         (B) The Corporation shall not permit any subsidiary of the Corporation
         to purchase or otherwise acquire for consideration any shares of stock
         of the Corporation unless the Corporation could, under paragraph (A) of
         this Section 4, purchase or otherwise acquire such shares at such time
         and in such manner.

                  Section 5. Reacquired Shares. Any shares of Series A Preferred
Stock purchased or otherwise acquired by the Corporation in any manner
whatsoever shall be retired and canceled promptly after the acquisition thereof.
All such shares shall upon their cancellation become authorized but unissued
shares of Preferred Stock and may be reissued as part of a new series of
Preferred Stock subject to the conditions and restrictions on issuance set forth
herein, in the Restated Certificate of Incorporation, or in any other
Certificate of Designations creating a series of Preferred Stock or any similar
stock or as otherwise required by law.

                  Section 6. Liquidation, Dissolution or Winding Up. Upon any
liquidation, dissolution or winding up of the Corporation, no distribution shall
be made (1) to the holders of shares of stock ranking junior (upon liquidation,
dissolution or winding up) to the Series A Preferred Stock unless, prior
thereto, the holders of shares of Series A Preferred Stock shall have received
$100 per share, plus an amount equal to accrued and unpaid dividends and
distributions thereon, whether or not declared, to the date of such payment,
provided that the holders of shares of Series A Preferred Stock shall be
entitled to receive an aggregate amount per share, subject to the provision for
adjustment hereinafter set forth, equal to 100 times the aggregate amount to be
distributed per share to holders of shares of Common Stock, or (2) to the
holders of shares of stock ranking on a parity (upon liquidation, dissolution or
winding up) with the Series A Preferred Stock, except distributions made ratably
on the Series A Preferred Stock and all such parity stock in proportion to the
total amounts to which the holders of all such shares are entitled upon such
liquidation, dissolution or winding up. In the event the Corporation shall at
any time declare or pay any dividend on the Common Stock payable in shares of
Common Stock, or effect a subdivision or combination or consolidation of the
outstanding shares of Common Stock (by reclassification or otherwise than by
payment of a dividend in shares of Common Stock) into a greater or lesser number
of shares of Common Stock, then in each such case the aggregate amount to which
holders of shares of Series A Preferred Stock were entitled immediately prior to
such event under the proviso in clause (1) of the preceding sentence shall be
adjusted by multiplying such amount by a fraction the numerator of which is the
number of shares of Common Stock outstanding immediately after such event and
the denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

                  Section 7. Consolidation, Merger, etc. In case the Corporation
shall enter into any consolidation, merger, combination or other transaction in
which the shares of Common Stock are exchanged for or changed into other stock
or securities, cash and/or any other property, then in any such case each share
of Series A Preferred Stock shall at the same time be similarly exchanged or
changed into an amount per share, subject to the provision for adjustment
hereinafter set forth, equal to 100 times the aggregate amount of stock,
securities, cash and/or any other property (payable in kind), as the case may
be, into which or for which each share of Common Stock is changed or exchanged.
In the event the Corporation shall at any time declare or pay any dividend on
the Common Stock payable in shares of Common Stock, or effect a
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subdivision or combination or consolidation of the outstanding shares of Common
Stock (by reclassification or otherwise than by payment of a dividend in shares
of Common Stock) into a greater or lesser number of shares of Common Stock, then
in each such case the amount set forth in the preceding sentence with respect to
the exchange or change of shares of Series A Preferred Stock shall be adjusted
by multiplying such amount by a fraction, the numerator of which is the number
of shares of Common Stock outstanding immediately after such event and the
denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

                  Section 8. No Redemption. The shares of Series A Preferred
Stock shall not be redeemable.

                  Section 9. Rank. The Series A Preferred Stock shall rank, with
respect to the payment of dividends and the distribution of assets, junior to
all series of any other class of Preferred Stock.

                  Section 10. Amendment. The Restated Certificate of
Incorporation of the Corporation shall not be amended in any manner which would
materially alter or change the powers, preferences or special rights of the
Series A Preferred Stock so as to affect them adversely without the affirmative
vote of the holders of at least two-thirds of the outstanding shares of Series A
Preferred Stock, voting together as a single class.

                  IN WITNESS WHEREOF, Huttig Building Products, Inc. has caused
this Certificate of Designations of Series A Junior Participating Preferred
Stock to be duly executed by its President and Chief Executive Officer this 6th
day of December, 1999.

                                           Huttig Building Products, Inc.

                                           /s/ Barry J. Kulpa
                                           -------------------------------------
                                           Barry J. Kulpa
                                           President and Chief Executive Officer

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