D.C. Mun. Regs. tit. 14, r. 14-4713
The owner shall afford the tenant a reasonable period to negotiate a contract of sale and shall not require less than sixty (60) days to negotiate a contract. For every day of delay beyond the seven (7) days in which the owner is required to provide information under §§ 4711.4(c) and (d), the negotiation period shall be extended by one (1) day.
The owner shall afford the tenant a reasonable period prior to settlement and shall not require less than sixty (60) days from the date of contract.
The owner shall afford an extension of time consistent with a written estimate from a lending institution or agency that normally provides financing if a decision with respect to financing or financial assistance will be made within ninety (90) days after the date of contract.
If one hundred eighty (180) days elapse from the date of a bona fide offer to sell under this section and the owner has not sold or contracted to sell the accommodation, the owner shall comply anew with the requirements of Title IV of the Act.
D.C. Mun. Regs. tit. 14, r. 14-4713