No person shall erect or construct or proceed with the erection or construction of any building or structure nor add to, enlarge, move, improve, alter, repair, convert, extend or demolish any building or structure or cause the same to be done in any zoned district in the City of Katy without first applying for and obtaining a building permit therefor. All applications for such permits shall be in accordance with the requirements of this ordinance and the Building Code of the City of Katy unless upon written order of the Board of Adjustment [and] no such building permit or certificate of occupancy shall be issued for any building where such construction, addition, alteration or use thereof would be in violation of the provisions of this ordinance.