Change Order / Variation Calculator

Under AIA A201-2017 Section 7.2, a Change Order is a written instrument signed by the owner, contractor, and architect stating their agreement upon a change in the work, amount of contract sum adjustment, and extent of contract time extension.

Under FIDIC Red/Yellow Book Clause 13.1, a Variation is an instruction issued by the Engineer to alter, add, omit, or substitute work, valued according to Clause 12 or Clause 13.3 procedures.

OH&P markup is applied to direct labor, material, and equipment costs. A typical 15% markup increases a $50,000 direct cost by $7,500 to $57,500.

Yes. Most public and commercial contracts allow 1% to 2% bond and risk insurance adjustment on the total subtotal of direct cost plus OH&P markup.

Per AIA A201 § 7.3, a Construction Change Directive orders a change in the work prior to final agreement on contract price or time adjustment.

Additive change orders increase contract scope and sum; deductive change orders omit scope and credit the owner, typically excluding profit overhead recovery.

Cumulative change orders exceeding 10% to 15% of original contract value signal scope creep, potential dispute risk, and increased surety bond exposure.

Approved change orders modify the contract line item baseline on monthly payment applications (AIA G702/G703 or FIDIC IPC submissions).