D.C. Mun. Regs. tit. 17, r. 17-1805
In the provision of professional design services, a professional design firm shall be subject to the applicable rules of professional conduct and any standards of practice established in Chapters 19 (Landscape Architects), 32 (Interior Designers), and 34 (Architects) of this title.
All architecture services solicited or provided by a professional design firm shall be under the responsible charge of a supervising architect who is licensed in the District.
All interior design services solicited or provided by a professional design firm shall be under the responsible charge of a supervising architect or interior designer who is licensed in the District
All landscape architecture services solicited or provided by a professional design firm shall be under the responsible charge of a supervising landscape architect who is licensed in the District.
No person shall sign and stamp a professional design document on behalf of a professional design firm except an architect, interior designer, or landscape architect licensed in the District.
D.C. Mun. Regs. tit. 17, r. 17-1805