Which of the following is NOT a requirement to start the design development phase?

The design development phase is a critical step in the architectural process that comes after the schematic design phase. During this stage, the architect refines the design into more detailed specifications and drawings, which help to guide the subsequent phases of the project.

Having a client-approved schematic design is fundamental as it serves as the blueprint for what the project will entail. An agreed construction budget is essential because it ensures that the design aligns with the financial constraints and expectations of the client, allowing the architect to make informed decisions regarding materials and methods. Additionally, agreement on sustainability targets is increasingly important as projects aim to meet specific environmental standards and efficiency goals.

However, final construction drawings are not a requirement to start the design development phase. In fact, final construction drawings are created after the design development phase has been completed. This distinction is crucial, as design development involves refining and expanding upon initial designs rather than finalizing them. Therefore, starting the design development phase does not necessitate having final construction drawings, making this option the correct answer in this context.