Exhibit 5.1 August 12, 1999 Atrium Companies, Inc. 1341 W. Mockingbird Lane, Suite 1200W Dallas, Texas 75247 ATRIUM COMPANIES, INC. REGISTRATION STATEMENT ON FORM S-4 Ladies and Gentlemen: This opinion is delivered in our capacity as counsel to Atrium Companies, Inc., a Delaware corporation (the "Issuer"), in connection with the Issuer's registration statement on Form S-4 (the "Registration Statement") filed with the Securities and Exchange Commission (the "Commission") under the Securities Act of 1933, as amended, relating to the offering by the Issuer of $175,000,000 aggregate principal amount of its 10-1/2% Senior Subordinated Notes due 2009, Series B (collectively, the "Notes"). In connection with this opinion, we have examined copies or originals of such documents, resolutions, certificates and instruments of the Issuer as we have deemed necessary to form a basis for the opinion hereinafter expressed. In addition, we have reviewed certificates of public officials, statutes, records and other instruments and documents as we have deemed necessary to form a basis for the opinion hereinafter expressed. In our examination of the foregoing, we have assumed, without independent investigation, (i) the genuineness of all signatures, and the authority of all persons or entities signing all documents examined by us and (ii) the authenticity of all documents submitted to us as originals and the conformity to authentic original documents of all copies submitted to us as certified, conformed or photostatic copies. With regard to certain factual matters, we have relied, without independent investigation or verification, upon statements and representations of representatives of the Issuer. Based upon and subject to the foregoing, we are of the opinion that, as of the date hereof, when the Notes have been duly authenticated by the State Street Bank and Trust Atrium Companies, Inc. August 12, 1999 Page 2 Company, in its capacity as Trustee, and duly executed and delivered on behalf of the Issuer against payment therefor as contemplated by the Registration Statement, the Notes will be legally issued and will constitute a binding obligation of the Issuer, subject to applicable bankruptcy, insolvency, reorganization, fraudulent conveyance and transfer, moratorium or other laws now or hereafter in effect relating to or affecting the rights or remedies of creditors generally and by general principles of equity (whether applied in a proceeding at law or in equity) including, without limitation, standards of materiality, good faith and reasonableness in the interpretation and enforcement of contracts, and the application of such principles to limit the availability of specific equitable remedies such as specific performance. We hereby consent to being named as counsel to the Issuer in the Registration Statement, to the references therein to our firm under the caption "Legal Matters" and to the inclusion of this opinion as an exhibit to the Registration Statement. In giving this consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act of 1933, as amended, or the rules and regulations of the Commission thereunder. Very truly yours, /s/ PAUL, HASTINGS, JANOFSKY & WALKER LLP