Which type of contract allows the project to start before all plans are complete?

The phased or fast track contract is designed to allow construction to commence before all plans and specifications are fully completed. This approach enables different parts of the project to be constructed simultaneously or in phases, which can significantly reduce the overall timeline for project completion.

This method is particularly beneficial in scenarios where time is of the essence, allowing the team to expedite various elements of construction while final details are still being ironed out. It encourages flexible project management and can be particularly useful in complex projects where waiting for full design completion would lead to delays.

In contrast, fixed-price contracts typically require finalized plans before any work begins, as the contractor needs a clear understanding of the scope to provide an accurate price. Cost-plus contracts, while flexible in terms of expenses, also do not inherently facilitate starting construction early, as they depend on defined scope and costs. Design-bid-build is a traditional method where the design is completed before bidding and construction begins, hence it does not allow for overlapping design and construction phases.