(a) Except as otherwise provided in subsection (b) or as otherwise authorized by law, the Secretary concerned may not construct or acquire military family housing units unless the number of units to be constructed or acquired has been specifically authorized by law.

(b) Subsection (a) does not apply to the following:

(1) Housing units acquired under section 404 of the Housing Amendments of 1955 (42 U.S.C. 1594a).

(2) Housing units leased under section 2828 of this title.

(3) Housing units acquired under the Homeowners Assistance Program referred to in section 2832 of this title.

(4) Housing units acquired without consideration.

(5) Replacement housing units constructed under section 2825(c) of this title.

(6) Housing units constructed or provided under section 2869 of this title.