It is always best to make changes before work has begun and before the contract is signed. If you change your mind before the final contract is written and signed, call your contractor immediately and tell him or her what changes you want to make. S/he can then incorporate the change into the final contract and the final cost in the contract. If the contract has been signed, you should discuss it with your contractor and write a detailed change order that includes any effect of the change on the cost of the project. You and the contractor should both sign the completed change order. Each of you should keep a copy with your records.