661—201.4 (100) Existing buildings or structures. Additions or alterations to any building or structure shall comply with the requirements of this chapter for new construction. Additions or alterations shall not be made to an existing building or structure that will cause the existing building or structure to be in violation of any provisions of 661—Chapter 201. An existing building plus additions shall comply with the height and area provisions of Chapter 5 of the International Building Code, 2006 edition. Portions of the structure not altered and not affected by the alteration are not required to comply with the requirements established in 661—Chapter 201 for a new structure.