Exhibit 16.1

Deloitte & Touche LLP

Suite 4500

1111 Bagby Street

Houston, TX 77002-2591

USA

Tel: 1+713 982 2000

Fax: 1+713 982 2001

www.deloitte.com

April 15, 2014

Securities and Exchange Commission

100 F Street, N.E.

Washington, D.C. 20549-7561

Dear Sirs/Madams:

We have read Item 4 of Quanex Building Products Corporation’s Form 8-K dated April 14, 2014, and have the following comments:

1. We agree with the statements made in paragraphs 2-5.

2. We have no basis on which to agree or disagree with the statements made in paragraphs 1 and 6.

Yours truly,

Member of                                            

Deloitte Touche Tohmatsu Limited