NONQUALIFIED STOCK OPTION AGREEMENT FOR EXECUTIVE OFFICERS

Exhibit 10(iii)A(5)

NONQUALIFIED STOCK OPTION AGREEMENT

FOR EXECUTIVE OFFICERS

THIS AGREEMENT, made as of January 20, 2004 (the “Grant Date”), between Acuity Brands, Inc., a Delaware corporation (the “Company”), and Vernon J. Nagel (the “Optionee”).

WHEREAS, the Company has adopted the Acuity Brands, Inc. Long-Term Incentive Plan (the “Plan”) in order to provide additional incentive to certain officers and key employees of the Company and its Subsidiaries; and

WHEREAS, the Optionee performs services for the Company and/or one of its Subsidiaries; and

WHEREAS, the Committee responsible for administration of the Plan has determined to grant the Option to the Optionee as provided herein.

NOW, THEREFORE, the parties hereto agree as follows:

1.1 The Company hereby grants to the Optionee the right and option (the “Option”) to purchase all or any part of an aggregate of 150,000 whole Shares subject to, and in accordance with, the terms and conditions set forth in this Agreement and the Plan.

1.2 The Option is not intended to qualify as an Incentive Stock Option within the meaning of Section 422 of the Code.

1.3 This Agreement shall be construed in accordance and consistent with, and subject to, the provisions of the Plan (the provisions of which are incorporated herein by reference) and, except as otherwise expressly set forth herein, the capitalized terms used in this Agreement shall have the same definitions as set forth in the Plan.

1.4 The Option is conditioned upon Optionee’s execution of this Agreement. If the Agreement is not executed by the Optionee, the Option may be canceled by the Committee.

The price at which the Optionee shall be entitled to purchase Shares upon the exercise of the Option shall be $31.00 per Share.

The Option shall be exercisable to the extent and in the manner provided herein for a period of ten (10) years from the Grant Date (the “Exercise Term”); provided, however, that the Option may be earlier terminated as provided in Sections 1.4 and 6 hereof.

The Option shall vest, and may be exercised, with respect to the Shares as set forth in the Optionee Statement attached hereto and made a part hereof, subject to earlier termination of the Option as provided in Sections 1.4 and 6 hereof or in the Plan. The right to purchase the Shares as they become vested shall be cumulative and shall continue during the Exercise Term unless sooner terminated as provided herein.

5.1 Subject to the terms and conditions of this Agreement and the Plan, the Option may be exercised by either (i) delivery of written notice to the Company, at its principal executive office or (ii) online notice given to an online broker with which the Company has made arrangement for the exercise of employee stock options, which notice satisfies the form and conditions set forth in such arrangement, which shall be provided to the Grantee from time to time. Such notice shall state that the Optionee is electing to exercise the Option and the number of Shares in respect of which the Option is being exercised and, if delivered in writing to the Company, shall be signed by the person or persons exercising the Option. If requested by the Committee, such person or persons shall (i) deliver this Agreement to the Secretary of the Company who shall endorse thereon a notation of such exercise and (ii) provide satisfactory proof as to the right of such person or persons to exercise the Option.

5.2 The notice of exercise described in Section 5.1 shall be accompanied by the full purchase price for any Shares purchased pursuant to the exercise of an Option and shall be paid in full upon such exercise, (i) in cash, by check, by transferring Shares to the Company or by attesting to the ownership of Shares, upon such terms and conditions as may be acceptable to the Committee or (ii) by such arrangement as is made by the Company with the designated online broker. Any Shares the Optionee transfers to the Company or attests to owning as payment of the purchase price under an Option shall be valued at their Fair Market Value on the day preceding the date of exercise of such Option.

5.3 Upon receipt of notice of exercise and full payment for the Shares in respect of which the Option is being exercised, the Company shall, subject to Section 16 of the Plan, take such action as may be necessary to effect the transfer to the Optionee of the number of Shares as to which such exercise was effective.

5.4 The Optionee shall not be deemed to be the holder of, or to have any of the rights of a holder with respect to any Shares subject to the Option until (i) the Option shall have been exercised pursuant to the terms of this Agreement and the Optionee shall have paid the full purchase price for the number of Shares in respect of which the Option was exercised, (ii) the Company shall have issued and delivered the Shares to the Optionee, and (iii) the Optionee’s name shall have been entered as a stockholder of record on the books of the Company, whereupon the Optionee shall have full voting and other ownership rights with respect to such Shares.

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If the employment of the Optionee with the Company and its Subsidiaries shall terminate for any reason, other than for the reasons set forth in Sections 6.2 and 7.2 below, the Option shall continue to be exercisable (to the extent the Option was vested and exercisable on the date of the Optionee’s termination of employment) at any time within three (3) months after the date of such termination of employment, but in no event after the expiration of the Exercise Term.

If the Optionee’s termination of employment is due to death, Disability, or Retirement (termination on or after age 65), or if Optionee terminates employment after age 55, the following shall apply: