1. Any alteration of a nonconforming sign that requires a building permit;

2. Any alteration of a structure or building on the property that requires a building permit and a certificate of occupancy;

3. Additions or expansions of 25 percent or more of the overall square footage of a structure or building on the property;

4. Any change to a property that requires a building permit of which the value of the building permit improvements is 25 percent or more of the real market value of the buildings on the property within a 24-month period, as determined by the Yamhill County assessor’s office in the most recent tax year;

5. Abandonment of a nonconforming sign.