Me. Rev. Stat. tit. 10, § 1488

Each change order to a home construction contract must be in writing and becomes a part of and is in conformance with the existing contract. All work shall be performed under the same terms and conditions as specified in the original contract unless otherwise stipulated. The change order must detail all changes to the original contract that result in a revision of the contract price. The previous contract price must be stated and the revised price shall also be stated. Both parties must sign the change order.