48 CFR §570.501

1. (a)The procedures in 570.502 apply to alterations acquired directly from a lessor by modification or supplemental lease agreement. This is allowed if the following conditions are met:
   1. (1)The alterations fall within the scope of the lease. Consider whether the work can be regarded fairly and reasonably as part of the original lease requirement.
   2. (2)The lessor is willing to perform the proposed alterations at a fair and reasonable price.
   3. (3)It is in the Government's interest to acquire the alterations from the lessor.
2. (b)If proposed alterations are outside the scope of the existing lease, decide whether to acquire the alterations through either:
   1. (1)A supplemental lease agreement, as justified and approved under 570.502-1.
   2. (2)Government performance or a separate contract. The lease must first provide the Government the right to perform alterations to the leased space.