Estimation & BOQ Preparation

Estimation in civil engineering refers to the process of calculating the overall costs of a project before it begins. The aim is to predict the expenses associated with materials, labor, equipment, and other resources necessary to complete the project. Accurate estimation is crucial for project planning, budgeting, and controlling costs throughout the construction phase.

Types of Estimation in Civil Engineering

1. Preliminary Estimate:
   • Description: This is an early, rough estimate prepared during the initial phase of the project. It is based on available information and serves as a budget guideline for clients or investors. It provides an approximate idea of the project cost based on past experience or similar projects.
   • Usage: Used for deciding on the feasibility of the project and securing funding.
   • Methods:
     • Approximate Quantity Method: Cost is estimated based on the unit cost of materials and labor required for the project.
     • Plinth Area Method: Cost is based on the floor area (plinth area) of the structure.
2. Detailed Estimate:
   • Description: A comprehensive and accurate estimate prepared after the design has been finalized. It includes detailed calculations for all quantities and costs of materials, labor, overheads, and other expenses involved.
   • Usage: This estimate is used to determine the final project cost and to secure contracts with contractors and suppliers.
   • Methods:
     • Quantity Surveying: Detailed calculation of quantities of materials required, followed by cost estimation for each item.
     • Rate Analysis: Breaking down the cost of each item into sub-components like material, labor, overheads, and profit margin.
3. Unit Rate Estimate:
   • Description: The project cost is determined by the unit rates for various items of work (e.g., per cubic meter for excavation or per square meter for plastering). The rates are calculated based on the quantities needed for each task.
   • Usage: Common in projects that are tendered, where unit rates are used to submit bids.
4. Structural Estimate:
   • Description: This type of estimate is specific to the construction of structural elements (e.g., beams, columns, slabs, foundations). It includes the quantities of steel, concrete, and other materials used in structural components.
   • Usage: It helps ensure that the structural materials are estimated accurately and in line with design specifications.
5. Cost Plus Estimate:
   • Description: In this method, the client agrees to pay for all project costs plus an additional fee for the contractor's profit. It is typically used when the scope of work cannot be fully defined upfront.
   • Usage: Useful in cases where unforeseen conditions might alter the project scope during construction.
6. Resource-Cost Estimate:
   • Description: This estimate involves calculating the cost of the resources used in the project, including labor, materials, and equipment. It includes both direct and indirect costs associated with the construction work.
   • Usage: Used for comprehensive project planning and to allocate resources efficiently.