Revised Estimate:

Due to change in the rate of material or change in specification of materials, an estimate is often required to be modified. Thus, we prepare revised estimate against the original estimate. In the preparation of revised estimate, original estimate is also provided such that comparison can be made. There is no change in structural drawing and additional items are not added in the revised estimate.

Revised estimate is a detailed estimate. It is also accompanied by the original estimate for comparative purpose. While submitting the revised estimate, the reason for revision should also be stated.

Supplementary estimate:

During the execution of project, structural modification are required or addition work is added for construction. The estimate for additional work is called supplementary estimate. Supplementary estimate is also required to be prepared when some of the items are overlooked. In preparing the supplementary estimate reason for preparing the estimate would be clearly stated.
Example: Additional partition can be planned in the building. The estimate is prepared for partitioning as supplementary estimate. Structural / architectural changes are prerequisite for supplementary estimate.