D.C. Mun. Regs. tit. 23, § 1717
1717.1 No document or other information shall be accepted for the record after the close of a hearing, except as follows:
(a) Until all parties are afforded due notice and an opportunity to rebut the information; or
(b) Upon official notice of a material fact not appearing in the evidence in the record, in accordance with D.C. Official Code § 2-509(b).
1717.2 The Board shall afford parties an opportunity to file Proposed Findings of Fact and Conclusions of Law within thirty (30) calendar days after the conclusion of the hearing. The parties may seek an extension to file Proposed Findings of Fact and Conclusions of Law if the transcript has not become available within twenty (20) calendar days. An extension granted by the Board shall not exceed twenty (20) calendar days after the transcript in the proceeding becomes available, by oral or written notice of the Board to each party.
1717.3 Proposed Findings of Fact and Conclusions of Law shall be typewritten on letter-sized (8.5" x 11") paper and double-spaced.
1717.4 An original and six (6) legible copies of Proposed Findings of Fact and Conclusions of Law shall be filed with the Board.
1717.5 A copy of the Proposed Findings of Fact and Conclusions of Law shall be served on each party.
SOURCE: Final Rulemaking published at 51 DCR 4309 (April 30, 2004); as amended by Final Rulemaking published at 55 DCR 12991 (December 26, 2008).