SC 13D/A

Number of

shares

beneficially

owned by

each

reporting

person

with

Sole voting power

0

Shared voting power

7,460,528.41 (See Item 5)

Sole dispositive power

0

Shared dispositive power

7,460,528.41 (See Item 5)

SC 13D/A 1 d113701dsc13da.htm SC 13D/A SC 13D/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 13D/A

Under the Securities Exchange Act of 1934

(Amendment No. 2)*

Cornerstone Building Brands, Inc.

(Name of Issuer)

Common Stock, $0.01 par value per share

(Title of Class of Securities)

628852204

(CUSIP Number)

Kirkland & Ellis LLP

300 North LaSalle

Chicago, Illinois 60654

Attn: Robert Goedert

(312) 862-2000

(Name, address and telephone number of person authorized to receive notices and communications)

March 8, 2021

(Date of event which requires filing of this statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. ☐

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240 13d-7 for other parties to whom copies are to be sent.

*	The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934, as amended (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 628852204


1.		Name of reporting person Atrium Intermediate Holdings, LLC
2.		Check the appropriate box if a member of a group (a) ☐ (b) ☒
3.		SEC use only
4.		Source of funds OO
5.		Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e) ☐
6.		Citizenship or place of organization Delaware

*	Based on 125,262,234 shares of common stock outstanding as of February 24, 2021, after giving effect to the Block Trade (as defined herein) as described in Item 4 hereof.

CUSIP No. 628852204


1.		Name of reporting person Atrium Window Holdings, LLC
2.		Check the appropriate box if a member of a group (a) ☐ (b) ☒
3.		SEC use only
4.		Source of funds OO
5.		Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e) ☐
6.		Citizenship or place of organization Delaware

SEC Form SC 13D/A filed