🕑 Reading time: 1 minuteUnit cost method of estimation in construction projects starts with dividing a project into various components or elements for the purpose of cost estimation. The cost of each of the project's components or elements are assessed and their cost estimation is calculated. Sum of costs of each project elements gives the total construction cost of the project. The unit cost method of estimation can be used for project design estimates as well as for bid estimates. Construction cost estimates are of three types mentioned below:
- Preliminary Cost Estimates
- Detailed Cost Estimates
- Engineer's Cost Estimates
For bid estimates, the unit cost method of estimation can also be used even though the contractor divides the project into different levels in a hierarchy as follows:
- Subcontractor Quotations: The general contractor of the construction project may get quotations for various items from the subcontractors. The rates prescribed by the subcontractors for various items of the projects can be used for the total construction cost etimate for the project. However, the reliability of accuracy of the cost depends on the method of cost estimates selected by the subcontractor.
- Quantity Takeoffs: The division of a construction project into various items of quantities that are measured from the engineer's plan will result in a procedure similar to that adopted for a detailed estimate or an engineer's estimate by the design professional. The levels of detail may vary according to the desire of the general contractor and the availability of cost data.
- Construction Procedures: If the construction procedure of a proposed project is used as the basis of a cost estimate, the project may be decomposed into items such as labor, material and equipment needed to perform various tasks in the projects.