The power to approve, or approve with conditions, or disapprove site plans as required by this article is vested in the Planning Board. Prior to issuing a building permit for the construction, expansion, conversion, or change in the occupancy or use of any apartment house, multiple-dwelling unit, commercial, industrial or manufacturing building or their accessory buildings or structures and before any permit for erection of a permanent building in a planned unit development shall be granted or before any subdivision plat or any part thereof may be filed in the office of the Monroe County Clerk, the authorized official shall refer the site plan and supporting documentation of such project to the Planning Board. All site plan information and dwelling designs shall be prepared by a licensed architect or engineer. "Expansion," as used above, shall refer to expansion of or addition to any existing building or structure, excepting expansions or additions less than 200 square feet in area, or less than 5% of the existing building area, whichever is less, if said expansions or additions do not materially affect other required site improvements or other aspects of the project requiring Planning Board approval. All plans shall show the seal and signature of said architect or engineer. In addition, the architect or engineer shall submit to the Town a signed affidavit that the plans for the project were prepared by said architect or engineer, his employees or by an agency of the federal, state or local government. No building permit shall be issued except in accordance with the standards and procedures set forth in this article.