- If within thirty days after receipt of any notice under section 337 or 342, or of the plan, section, description or further information, if any, called for under section 338, 340 or 343, as the case may be, the Commissioner fails to intimate in writing, to the person who has given the said notice, his disapproval of the building which the said person proposes to erect, or of the work which he proposes to execute;

or if, within the said period, the Commissioner signifies in writing to the said person his approval of the said building or work;

the said person may, at any time within one year from the date of the delivery of the notice to the Commissioner, proceed with the said building or work in accordance with his intention as described in the notice or in any of the documents aforesaid, but not so as to contravene any of the provisions of this Act or any by-law made under this Act at the time in force.