A firm hires a contractor to build a new warehouse.

Verbally notify the contractor of the changes, negotiate the costs, and instruct the contractor to proceed with the change and write the change order at the time of project completion

Develop a written description of the changes, and negotiate a written change order that minimizes the cost impact while work continues on the warehouse

Stop construction on the warehouse and negotiate the change order with the contractor before resuming work

Advise the contractor on how much the firm has available to build the new office area, and write a change order based on the final amount of the revisions