Final answer:
Conceptual planning estimates are based on general facility parameters such as size, construction quality, and intended use, providing early-stage cost approximations ahead of detailed design.
Step-by-step explanation:
Estimates of conceptual planning are primarily based on general parameters of facility size, anticipated quality of construction, and use of the facility.
During the initial stages of conceptual planning, the focus is on general parameters rather than detailed schematics. Before the proceedings to detailed design, which includes specific shapes and dimensions of all physical components, the conceptual estimates give a foundational cost framework based on broad facility characteristics. The mathematical models in this phase are less about precision and more about providing a ballpark figure that can guide early decision-making. This approach to estimating ensures that costs can be compared on a broad scale, such as cost per thousand gallons of water for engineering projects.
It's only in later stages that more precise itemized cost computations become relevant, when the design is further developed and precise measurements, materials, and other specific factors come into play, enabling prototypes and models to be created.