The Deputy Chief Financial Officer shall place unimproved real property that does not meet the requirements for Classes 1 through 4 into Class 5 beginning July 1, 1990 (real property tax year 1991).
For the purpose of Class 5 treatment only, the Deputy Chief Financial Officer shall consider real property to be improved if it has located on it permanently attached equipment used for commercial purposes that makes the land otherwise unbuildable, including storage tanks, railroad tracks and transmittal towers.
The Deputy Chief Financial Officer shall not place the following unimproved real property into Class 5:
If the Deputy Chief Financial Officer determines that an unimproved portion of an improved lot meets the requirements of Class 5, the Deputy Chief Financial Officer shall apportion the lot into the appropriate classes of real property.
D.C. Mun. Regs. tit. 9, r. 9-353