Which estimating method is typically prepared after the preliminary design is completed?

The area method is typically prepared after the preliminary design is completed because it provides a way to estimate construction costs based on the square footage of the building types being proposed. Once a preliminary design is developed, including the layout and the general dimensions of the project, architects and estimators can use the area method to calculate expected costs by applying square footage rates, which can be derived from historical data or market surveys.

This approach enables a relatively quick estimation process based on the overall size of the project, making it suitable during the design development phase when more specific cost details may not yet be available but an understanding of the project scale is clearer. As such, it aligns well with the timing after preliminary design completion when decisions about space and form have been substantially made.