Conceptual Estimate
A very early, rough cost projection built before a design is finished, usually based on square footage or a project's general type, accurate only within a wide range, often fifty to one hundred percent, rather than a precise number.
Why it matters
A conceptual estimate exists to answer one question early: is this project even in the right ballpark financially, before anyone spends real money designing it in detail. Treating a conceptual estimate as a firm budget, rather than the rough placeholder it actually is, is one of the most common sources of friction later in a project.
On a real project
Before any drawings exist, an estimator gives an owner a conceptual estimate for a new warehouse based on a typical dollar-per-square-foot cost for similar buildings, explicitly labeled as accurate only within a wide range, to help the owner decide whether to proceed into actual design.
Who this matters most to
An Estimator builds a conceptual estimate at the very start of a project, long before enough detail exists for a tighter number.
Where this goes wrong
An owner takes a conceptual estimate's wide range and quotes only the low end of it to investors as the expected cost. When the real, detailed estimate comes in higher, the owner blames the estimator for being wrong, when the actual mistake was treating a rough early number as a firm commitment.