An accessory structure or use must be limited to and located on the same lot with the use of the principal structure to which it is accessory. The total area of all accessory structures may not occupy more than 50% of the area of a required rear yard. Unless otherwise permitted or restricted by this subtitle, no accessory structure may exceed 15 feet in height. Unless otherwise permitted or restricted by this subtitle, accessory structures must comply with the yard requirements of the district. No accessory structure may be erected on any lot before construction of the principal structure to which it is accessory. If an accessory structure, such as an attached garage, is attached to a principal structure by any wall or roof construction, it is considered to be a part of the principal structure and must comply in all respects with the requirements of this Code that apply to the principal structure. Ord. 16-581