The restrictions set forth in this section and §§ 2003 and 2004 shall apply to nonconforming uses within structures, whether the structure is conforming or nonconforming.
Where the nonconforming use occupies only a portion of the structure, the restrictions in this section and §§ 2003 and 2004 shall apply only to that part of the structure devoted to the nonconforming use.
A nonconforming use shall not be extended to portions of a structure not devoted to that nonconforming use at the time of enactment or amendment of this title, or to another structure.
Ordinary repairs, alterations, or modernizations may be made to a structure or portion of a structure devoted to a nonconforming use. Structural alterations shall not be allowed, except those required by other municipal law or regulation; provided, that structural alterations shall be permitted to a lawfully existing, nonconforming flat or apartment house located within a Residence District.
A structure devoted to a nonconforming use shall not be enlarged, except if the enlargement is to be devoted to a conforming use.
A new structure shall not be erected to house a nonconforming use.
D.C. Mun. Regs. tit. 11, r. 11-2002