D.C. Mun. Regs. tit. 25, r. 25-C6427
The size of the equipment enclosure, room or area shall provide working space to perform routine operations.
Clearance shall be provided for all equipment as prescribed by the manufacturer to allow normal maintenance operation and removal without disturbing other piping or equipment.
Equipment enclosures, rooms or areas shall not be used for storage of chemical emitting corrosive fumes or for storage of other items to the extent that entrance to the room for inspection or operation of the equipment is impaired.
In rooms with fixed ceilings, the minimum ceiling height shall be eight feet (8 ft.).
Equipment enclosures, rooms or areas shall be lighted to provide thirty foot (30 ft.) candles of illumination at floor level.
D.C. Mun. Regs. tit. 25, r. 25-C6427