24 CFR § 40.2
As used in this part, the term residential structure means a residential structure (other than a privately owned residential structure and a residential structure on a military reservation):
(1) Constructed or altered by or on behalf of the United States;
(2) Leased in whole or in part by the United States after August 12, 1968, if constructed or altered in accordance with plans and specifications of the United States; or
(3) Financed in whole or in part by a grant or loan made by the United States after August 12, 1968, if such residential structure is subject to standards for design, construction, or alteration issued under authority of the law authorizing such grant or loan.