(a) reject the application or complaint if it is insufficient or defective;

(b) make investigations of the facts, conduct inspections, hold conferences, and require the filing of reports, evidence, affidavits, or other material relevant to the proceeding;

(c) forward to or make available for inspection by either party any relevant evidence, and afford an opportunity to file a rebuttal thereto;

(d) for good cause shown, except where prohibited by the RSL, accept for filing any papers, even though not filed within the time required by this Code;

(e) require any person to appear or produce documents or both pursuant to subpoena issued by the DHCR;

(f) consolidate two or more applications, complaints, or proceedings which have at least one ground in common;

(g) forward to any party a notice of action proposed to be taken;

(h) grant or order a hearing;

(i) on its own initiative or upon application of any affected owner or tenant, consolidate proceedings applicable to the same building or group of buildings or development, notwithstanding that the housing accommodations affected may be subject to different regulations; in any such consolidated proceedings the determination with respect to any housing accommodation shall be made in accordance with the appropriate law or regulation applicable to such accommodations. Proceedings once consolidated may be severed for good cause shown;

(j) on its own initiative, or at the request of a court of competent jurisdiction, or for good cause shown upon application of any affected party, expedite the processing of a matter; or

(k) sever issues within a proceeding for purposes of issuing an order and determination with respect to certain issues while reserving other issues for subsequent determination.