Building permit. No building shall be erected, moved, enlarged or structurally altered, and no excavation for any building shall be begun, and no land shall be used for any activity covered by this chapter unless a building permit has been issued by the Code Enforcement Officer. Notwithstanding the above, no such building permit shall be required for normal maintenance and repair work, for painting, interior decoration, landscaping and the construction or erection of any structure such as a utility shed or animal shelter where the total floor area is 100 square feet or less, unless such permit is required by the State of New York.