Types of Estimates

THERE ARE three common types of estimates. They are the conceptual estimate, preliminary estimate, and final or detailed estimate.

The conceptual estimate is an estimate prepared while the project is still in a conceptual state. The conceptual estimate is used to study the feasibility of a project or to compare two potential design alternatives (for example, a concrete structure versus a steel structure or three stories versus four stories). These estimates are based on a description of the project or on very limited drawings and as such are the least accurate type of estimate.

The preliminary estimate is an estimate prepared from a partially completed set of drawings. A preliminary estimate is often performed when the drawings are 35% to 50% complete and is used to check to see if the proposed design is on budget and to identify changes to the design that need to be made to meet the budget. Preliminary estimates may be performed any time before the bid. Preliminary estimates are more accurate than conceptual estimates.

Final or detailed estimates are used to prepare bids for construction projects and change orders. They are prepared from a complete or nearly completed set of drawings. Final or detail estimates are the most accurate type of estimate.