Electrical Estimating Methods, 4th Edition

CHAPTER 4 The Quantity Takeoff

The quantity survey or takeoff is the starting point for any estimate. The takeoff is the decomposition of the work shown on the plans and specifications into units of measure that can be priced. The amount of detail shown on electrical drawings is perhaps the least of any for the major trades. Much of the work is shown with symbols and graphics that illustrate the design. As a result, the electrical estimator must not only count the items shown on the drawings but also envision the completed work, including fittings, hangers, fasteners, devices, and cover plates. A precise and thorough quantity takeoff is the basis for a sound estimate. Errors or inaccuracies in this portion of the estimate are compounded during the pricing phase, regardless of how reliable the unit prices are.

The takeoff should be organized so that the information gathered can be used in other parts of the construction process. For example, a schedule for performing the work can be created from the estimate, specifically crew composition, labor-hours, and task definition. It should also be noted that if the bid is successful and the work is awarded, the estimate will serve as the basis for the performance measurement baseline for project control. Even material procurement and equipment rental terms will have their genesis in the takeoff.

In this chapter, we will explore the most common practices of taking off quantities for an electrical construction project and offer suggestions ...