D.C. Code tit. 42 § 42-3404.11

The following provisions apply to accommodations with 5 or more units:

(1) Tenant organization. -- In order to make a contract of sale with an owner, the tenants shall: (A) form a tenant organization with the legal capacity to hold real property, elect officers, and adopt bylaws, unless such a tenant organization exists in a form desired by the tenants; (B) file articles of incorporation; and (C) deliver an application for registration to the Mayor and the owner by hand or by certified mail within 45 days of receipt of a valid offer or the Mayor’s receipt of a copy of a valid offer, whichever is later. If, at the time of receipt of the valid offer, a tenant organization exists in a form desired by the tenants, the delivery of the application for registration to the Mayor and the owner by hand or by certified mail shall be within 30 days of receipt of a valid offer or the Mayor’s receipt of a valid offer, whichever is later. The application shall include the name, address, and phone number of tenant officers and legal counsel (if any); a copy of the articles of incorporation, as filed; a copy of the bylaws; documentation that the organization represents at least a majority of the occupied rental units as of the time of registration and such other information as the Mayor may require. Upon registration, the organization constitutes the sole representative of the tenants, and the prior offer of sale is deemed an offer to the organization;

(2) Negotiation period. -- The owner shall afford the tenant organization a reasonable period to negotiate a contract of sale, and shall not require less than 120 days from the date of receipt of the statement of registration. For every day of delay in providing information by the owner as required by this subchapter, the negotiation period is extended by 1 day;

(3) Time before settlement. --

(A) The owner shall afford the tenant organization a reasonable period prior to settlement in order to secure financing and financial assistance, and shall not require less than 120 days after the date of contracting. If a lending institution or agency estimates in writing that a decision with respect to financing or financial assistance will be made within 240 days after the date of contracting, the owner shall afford an extension of time consistent with that written estimate;

(B) If the tenant organization articles of incorporation provide, by the date of contracting, that the purpose of the tenant organization is to convert the accommodation to a nonprofit housing cooperative with appreciation of share value limited to a maximum of the annual rate of inflation, the owner shall require not less than 180 days after the date of contracting or such additional time as required by this section;

(4) Lapse of time. -- If 360 days elapse from the date of a valid offer under this subchapter and the owner has not sold or contracted for the sale of the accommodation, or in the case of an offer of sale given for the purposes of demolition or discontinuance of housing use, has not issued a notice to vacate for demolition or discontinuance of housing use, pursuant to § 42-3505.01(g) or (i), the owner shall comply anew with the terms of this subchapter; provided, that if the negotiation period has been extended pursuant to § 42-3404.02(a-1)(6) or (a-2)(2)(F), the 360-day limit described in this paragraph may be extended by one day for each day of the extension.