Page 115 of PMBOK stated "...change requests may require information on estimated schedule impacts and estimated cost impacts prior to approval";
Page 117 Section 22.214.171.124 stated "change requests that have an impact on project baselines should normally include information about the cost of implementing the change....";
Page 120 section 126.96.36.199 stated that in a change control meetings "assessing the impact of the changes is an essential part of the meeting" for decision-making;
Putting the above together, you will need some initial estimates on how much that change will impact the baselines so that the CCB can use that information to make a decision. Once a change request has been approved and implemented, you are require to determine whether there is a deviation between your actual performance vs. your estimates.
In essence, before submitting the change request, you will do some estimation on how the change will impact your baselines and then when change is approved and implemented, you will evaluate your planned vs. the actual performance.
Project managers usually evaluate the impacts first. Change request occurred when there is a difference in your planned vs. actual performance. When you submit change requests, you may have to provide information on estimated cost impacts and/or schedule impacts and also possible risks. Therefore, without any evaluation or estimates, it will be difficult for the CCB to review and approve your change request.