D.C. Mun. Regs. tit. 1, § 2929
2929.1 An Administrative Law Judge may consolidate (join) two (2) or more petitions if they present identical or similar issues, involve the same rental unit or housing accommodation, or involve other circumstances in which consolidation would be expedient and would not prejudice the parties. A party may file a motion to consolidate or an Administrative Law Judge may consolidate cases on his or her own motion.
2929.2 If the Administrative Law Judge determines that the issues raised in a tenant petition may affect other tenants or all tenants in the housing accommodation, the Administrative Law Judge may expand the scope of the proceeding to include all affected tenants.
2929.3 Before expanding the scope of the proceeding, the Administrative Law Judge shall provide notice to the affected tenants and the housing provider.
2929.4 That notice shall state the issues to be decided and shall advise the tenants that they have a right to participate in the proceedings and that any decision shall be binding on them.
2929.5 Tenants and the housing provider may present any arguments in support of or opposition to expanding the scope of the proceeding.
SOURCE: Final Rulemaking published at 53 DCR 5674, 5678 (July 14, 2006); as amended by Notice of Final Rulemaking published at 57 DCR 12541, 12578 (December 31, 2010).