When an existing detached house is converted to an attached or apartment building type and an addition is added to the existing building, the following regulations apply:

1. The addition must contain the same building materials as the existing structure;
2. The roof pitch and form of the addition shall be the same as the existing structure;
3. The height of the addition shall not exceed the height of the existing structure;
4. The building addition shall not cumulatively exceed 50% of the floor area of the existing structure; and
5. Additions made after September 1, 2013, which do not comply with paragraphs A through D. above shall not be used for conversions that add one or more dwelling units.