POWER OF ATTORNEY
Know all by these presents, that the undersigned hereby
constitutes and appoints each of James S. Metcalf, Theroux, Jeffrey S. Lee and Peter Talosig, or either of them signing
singly, and with full power of substitution, the undersigned's true and
lawful attorney-in-fact to:
(1) prepare, execute in the undersigned's name and on
the undersigned's behalf, and submit to the U.S.
Securities and Exchange Commission (the "SEC") a
Form ID, including amendments thereto, and any other
documents necessary or appropriate to obtain codes
and passwords enabling the undersigned to make
electronic filings with the SEC of reports required by
Section 16(a) of the Securities Exchange Act of 1934,
as amended, or any rule or regulation of the SEC;
(2) execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of
Cornerstone Building Brands, Inc. (the "Company"), Forms 3,
4, and 5, and amendments thereto, in accordance with
Section 16(a) of the Securities Exchange Act of 1934,
as amended, and the rules thereunder;
(3) do and perform any and all acts for and on behalf of
the undersigned which may be necessary or desirable
to complete and execute any such Form 3, 4, or 5,
complete and execute any amendment or
amendments thereto, and timely file such form with the
SEC and any stock exchange or similar authority; and
(4) take any other action of any type whatsoever in
connection with the foregoing which, in the opinion of
such attorney-in-fact, may be of benefit to, in the best
interest of, or legally required by, the undersigned, it
being understood that the documents executed by
such attorney-in-fact on behalf of the undersigned
pursuant to this Power of Attorney shall be in such
form and shall contain such terms and conditions as
such attorney-in-fact may approve in such
attorney-in-fact's discretion.
The undersigned hereby grants to each such attorney-in-fact
full power and authority to do and perform any and every act and
thing whatsoever requisite, necessary, or proper to be done in the
exercise of any of the rights and powers herein granted, as fully to all
intents and purposes as the undersigned might or could do if
personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-fact, or such
attorney-in-fact's substitute or substitutes, shall lawfully do or cause
to be done by virtue of this power of attorney and the rights and
powers herein granted. The undersigned acknowledges that the
foregoing attorneys-in-fact, in serving in such capacity at the request
of the undersigned, are not assuming, nor is the Company
assuming, any of the undersigned's responsibilities to comply with
Section 16 of the Securities Exchange Act of 1934.
This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3, 4, and 5
with respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing
attorneys-in-fact.
IN WITNESS WHEREOF, the undersigned has caused this
Power of Attorney to be executed as of 03-08, 2021.
/s/ Alena Brenner
Signature
Alena Brenner
Print Name
