CEO — Donald A. Nolan: The filing discloses a short-term contract extension for the CEO to bridge the gap until a successor is found, rather than an immediate departure or a routine appointment.

of this Current Report on Form 8-K and Exhibit 99.1 attached hereto shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, and shall not be deemed to be incorporated by reference into any registration statement or other document filed pursuant to the Securities Act of 1933, as amended.

Completion of Acquisition or Disposition of Assets. On September 18, 2026, Apogee Enterprises, Inc. (the “Company”) completed the transaction contemplated by the Share Purchase Agreement, dated September 2, 2026 (the “Purchase Agreement”), pursuant to which Tiger MergeCo SIA, a wholly owned subsidiary of the Company, acquired all of the outstanding equity interests of SIA “Alzette” a Latvian limited liability company, and its subsidiaries, including GroGlass. Pursuant to the terms and conditi…

Director — Julie K. Streich: The filing discloses the routine election of new directors and the orderly retirement of a sitting director, which are standard board governance events rather than executive departures.

Entry into a Material Definitive Agreement Share Purchase Agreement On September 2, 2026, Apogee Enterprises, Inc. (the “Company”) entered into a Share Purchase Agreement (the “Purchase Agreement”) with the sellers party thereto (collectively, the “Sellers”), pursuant to which the Company, through a newly formed, wholly owned subsidiary, agreed to acquire 100% of the issued and outstanding equity interests of SIA “Alzette”, a Latvian limited liability company (“Alzette”) (the “Transaction”).…

The information furnished pursuant to this Item 7.01, including Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities under that section, and shall not be deemed to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Exchange Act, unless specifically identified therein as being incorporated therein by…

Director — Joseph B. Hayek, Suresh Krishna: Election of new directors to the Board.

Completion of Acquisition or Disposition of Assets. On July 1, 2026, Apogee Enterprises, Inc. (the “Company”) completed the transaction contemplated by the Merger Agreement, dated May 27, 2026 (the “Merger Agreement”), among the Company, Keller Companies, Inc. (“KCI”), certain equityholders party thereto and the other parties thereto. Pursuant to the terms and conditions of the Merger Agreement, the Company acquired all of the outstanding equity interests of KCI and its subsidiaries, includin…

of the Company’s Current Report on Form 8-K filed on May 28, 2026 with the U.S. Securities and Exchange Commission (the “SEC”). The foregoing description of the Merger Agreement and the transactions contemplated thereby does not purport to be complete and is subject to, and qualified in its entirety by, the full text of the Merger Agreement, a copy of which was filed with the SEC as Exhibit 2.1 to the Company’s Current Report on Form 8-K on May 28, 2026 and is incorporated into this

of this Current Report on Form 8-K and Exhibit 99.1 attached hereto shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, and shall not be deemed to be incorporated by reference into any registration statement or other document filed pursuant to the Securities Act of 1933, as amended.

President of the Architectural Glass Segment — Brent C. Jewell: Mr. Jewell tendered his resignation as President of the Architectural Glass Segment.

Entry into a Material Definitive Agreement Merger Agreement On May 27, 2026, Apogee Enterprises, Inc. (the “Company”) entered into a Merger Agreement (the “Merger Agreement”) with Keller Companies, Inc. (“KCI”) and KCI’s shareholders (the “Sellers”). KCI is the controlling shareholder of Kalwall Corporation (“Kalwall”) and Structures Unlimited Inc. (“SUI”). Subject to the terms and conditions of the Merger Agreement, the Company has agreed to acquire all of the outstanding equity interests of…

The information furnished pursuant to this Item 7.01, including Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities under that section, and shall not be deemed to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Exchange Act, unless specifically identified therein as being incorporated therein by…

The filing describes the awarding of restricted stock to executive officers, which is a routine compensation matter.

of this Current Report on Form 8-K and Exhibit 99.1 attached hereto shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, and shall not be deemed to be incorporated by reference into any registration statement or other document filed pursuant to the Securities Act of 1933, as amended.

CFO — Mark R. Augdahl: The filing announces the promotion of an existing interim CFO to the permanent Executive Vice President and CFO role, which is an internal succession rather than a departure.

of this Current Report on Form 8-K and Exhibit 99.1 attached hereto shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, and shall not be deemed to be incorporated by reference into any registration statement or other document filed pursuant to the Securities Act of 1933, as amended.

CFO — Matthew J. Osberg: The resignation of the sitting CFO is a significant executive departure, even with an interim successor, as it creates a leadership vacuum requiring a search.

CEO — Ty R. Silberhorn: The CEO departed but was immediately succeeded by the Independent Chair of the Board, indicating an orderly succession rather than a sudden loss of leadership.

of this Current Report on Form 8-K and Exhibit 99.1 attached hereto shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, and shall not be deemed to be incorporated by reference into any registration statement or other document filed pursuant to the Securities Act of 1933, as amended.

President — Troy R. Johnson: A long-time senior executive was promoted to President to succeed a resigning officer, representing an orderly internal succession rather than a loss of external talent or a sudden shock.

of this Current Report on Form 8-K and Exhibit 99.1 attached hereto shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, and shall not be deemed to be incorporated by reference into any registration statement or other document filed pursuant to the Securities Act of 1933, as amended.

Chief Human Resources Officer — Raelyn A. Trende: The resignation of the Chief Human Resources Officer is a genuine executive departure, but the appointment of an interim successor mitigates the negative impact.

Director — Frank G. Heard: The filing discloses the planned retirement of a director who will not stand for re-election, which is an orderly succession rather than a sudden loss of a senior executive.

of this Current Report on Form 8-K and Exhibit 99.1 attached hereto shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, and shall not be deemed to be incorporated by reference into any registration statement or other document filed pursuant to the Securities Act of 1933, as amended.