Which of the following is a type of requirement?

• A. External
• B. Functional
• C. Performance
• D. Prescriptive

Answer: (B)

In DBIA practice, requirements are described in terms of what the project must do. Functional requirements specify the functions or services the building must provide for its users, focusing on the intended use and operations rather than prescribing exact solutions. This makes them a primary type of owner requirement because they set the what, not the how.

The other terms describe different ideas: external considerations are factors outside the project’s design, performance requirements set measurable outcomes the project must meet, and prescriptive requirements specify particular materials or construction methods. Among these options, the one that directly names a category of requirement used to capture user and operational needs is the functional type.