(b)
At any time, the Secretary may, for the purposes of the Department of the Air Force, requisition the use and take possession of any building or space in any building, and its appurtenances, in the District of Columbia, other than—
(1)
a dwelling house occupied as such;
(2)
a building occupied by any other agency of the United States; or
(3)
space in such a dwelling house or building.
The Secretary shall determine, and pay out of funds appropriated for the payment of rent by the Department of the Air Force, just compensation for that use. If the amount of the compensation is not satisfactory to the person entitled to it, the Secretary shall pay 75 percent of it to that person, and the claimant is entitled to recover by action against the United States an additional amount that, when added to the amount paid by the Secretary, is determined by the court to be just compensation for that use.