Section 11.503 - Contract clauses(a) Use the clause at 52.211-11, Liquidated Damages-Supplies, Services, or Research and Development, in fixed-price solicitations and contracts for supplies, services, or research and development when the contracting officer determines that liquidated damages are appropriate (see 11.501(a)).(b) Use the clause at 52.211-12, Liquidated Damages-Construction, in solicitations and contracts for construction, other than cost-plus-fixed-fee, when the contracting officer determines that liquidated damages are appropriate (see 11.501(a)). If the contract specifies more than one completion date for separate parts or stages of the work, revise paragraph (a) of the clause to state the amount of liquidated damages for delay of each separate part or stage of the work.(c) Use the clause at 52.211-13, Time Extensions, in solicitations and contracts for construction that use the clause at 52.211-12, Liquidated Damages-Construction, when that clause has been revised as provided in paragraph (b) of this section.