Which method allows for a single entity to oversee both the design and construction phases?

The Design-Build method is the correct answer because it integrates both the design and construction phases under a single contractual entity. This approach allows for streamlined communication, improved collaboration, and a more cohesive process from conceptual design through to project completion. The design-build entity is responsible for both creating the design and executing the construction, which can lead to faster project delivery and potentially reduced costs. As the contractor and designer work together as a unified team, it helps to minimize disputes and miscommunication, fostering a more efficient workflow.

In contrast, other methods like Design-Bid-Build separate design and construction responsibilities, leading to a more fragmented process. Joint ventures involve two or more parties working together but do not inherently consolidate the design and construction efforts under one entity. Project management is focused on overseeing the overall project execution and may involve multiple contracts, which does not provide the same integration as the design-build approach.