Generally, the more detailed a contract is, the fewer the problems that will come up later. A big project should have a detailed contract. Make sure you understand what the contract does and does not cover. Do not sign the contract unless you fully understand everything. Make Changes in Writing.
People change their minds during a building project.
If changes are made at the right time, the cost and length of the job may not be affected. Delay, however, can mean costly changes. For remodeling and new home projects, allow at least a 10 percent increase for changes from the contract. If changes in the plans or contract occur during the project, put them in writing as amendments to the contract, including any differences in cost. Both you and the contractor should sign the change orders.