D.C. Code § 42-3505.01

(d) A natural person with a freehold interest in the rental unit may recover possession of a rental unit where the person seeks in good faith to recover possession of the rental unit for the person’s immediate and personal use and occupancy as a dwelling. The housing provider shall serve on the tenant a 90-day notice to vacate in advance of action to recover possession of the rental unit in instances arising under this subsection. No housing provider shall demand or receive rent for any rental unit which the housing provider has repossessed under this subsection during the 12-month period beginning on the date the housing provider recovered possession of the rental unit. A stockholder of a cooperative housing association with a right of possession in a rental unit may exercise the rights of a natural person with a freehold interest under this subsection.

(e) A housing provider may recover possession of a rental unit where the housing provider has in good faith contracted in writing to sell the rental unit or the housing accommodation in which the unit is located for the immediate and personal use and occupancy by another person, so long as the housing provider has notified the tenant in writing of the tenant’s right and opportunity to purchase as provided in Chapter 34 of this title. The housing provider shall serve on the tenant a 90-day notice to vacate in advance of the housing provider’s action to recover possession of the rental unit. No person shall demand or receive rent for any rental unit which has been repossessed under this subsection during the 12-month period beginning on the date on which the rental unit was originally repossessed by the housing provider.