A conceptual estimate is an initial cost and/or time estimation of a construction project made prior to the development of detailed designs. It uses broad assumptions about scope, materials, labor, and other factors in order to provide an early indication as to what costs may be entailed in the project. A conceptual estimate is typically used by clients in order to gain a rough idea of what the budget or timeline for the project might look like, which can then inform further decision-making around contracting and design choices.
The accuracy of a conceptual estimate can vary significantly depending on the complexity of the project, as well as any changes that occur throughout its execution. As such, it should not be considered an exact representation of what will ultimately be spent or how long the project will take. Rather, it provides a general indication of the scope, cost, and timeline for a given project.