48 CFR § 36.214 - Special procedures for price negotiation in construction contracting.
(a) Agencies shall follow the policies and procedures in part 15 when negotiating prices for construction.
(b) The contracting officer shall evaluate proposals and associated certified cost or pricing data and data other than certified cost or pricing data and shall compare them to the Government estimate.
(1) When submission of certified cost or pricing data is not required (see 15.403–1 and 15.403–2), and any element of proposed cost differs significantly from the Government estimate, the contracting officer should request the offeror to submit cost information concerning that element (e.g., wage rates or fringe benefits, significant materials, equipment allowances, and subcontractor costs).
(2) When a proposed price is significantly lower than the Government estimate, the contracting officer shall make sure both the offeror and the Government estimator completely understand the scope of the work. If negotiations reveal errors in the Government estimate, the estimate shall be corrected and the changes shall be documented in the contract file.
(c) When appropriate, additional pricing tools may be used. For example, proposed prices may be compared to current prices for similar types of work, adjusted for differences in the work site and the specifications. Also, rough yardsticks may be developed and used, such as cost per cubic foot for structures, cost per linear foot for utilities, and cost per cubic yard for excavation or concrete.