What method involves individually estimating units of materials and labor for each task?

The quantity take-off method involves the detailed estimation of materials and labor required for each task in a construction project. This method focuses on counting and measuring the quantities of various elements needed to complete specific construction activities. By breaking down each part of the project into individual units, estimators can more accurately assess the resources required, leading to a more precise overall project budget.

In construction estimation, this method is essential as it provides a clear understanding of what each task entails and allows for better planning and resource allocation. It also helps in identifying potential cost-saving opportunities and optimizing project execution.

The other methods mentioned, while related to project estimation, operate on broader concepts or considerations rather than focusing on detailed task-specific estimations. For instance, project overhead refers to the indirect costs associated with project execution, contingencies involve adding a buffer for unexpected costs, and bid estimation is a comprehensive approach to determining the total project cost rather than breaking it down into individual tasks. Thus, the quantity take-off method is the most direct approach for estimating tasks based on individual material and labor needs.