5 U.S.C. § 5923: Quarters allowances

for a period not in excess of 90 days after first arrival at a new post of assignment in a foreign area or a period ending with the occupation of residence quarters, whichever is shorter; and for a period of not more than 30 days immediately before final departure from the post after the necessary evacuation of residence quarters. A living quarters allowance for rent, heat, light, fuel, gas, electricity, and water, without regard to section 3324(a) and (b) of title 31. the expenses are administratively approved in advance; and the duration and terms of the lease justify payment of the expenses by the Government. The 90-day period under subsection (a)(1)(A) and the 30-day period under subsection (a)(1)(B) may each be extended for not more than 60 additional days if the head of the agency concerned or his designee determines that there are compelling reasons beyond the control of the employee for the continued occupancy of temporary quarters.