Architect-led design-build is a delivery method in which the architect holds the primary contract with the client and subcontracts construction to a builder. Contractor-led design-build is when the builder holds the primary contract and subcontracts design to an architect. A third model, which is what Kingdom & Co. typically operates for outside-architect projects, is a partnership where the architect and the design-build firm collaborate on separate contracts with the same client, and each retains authorship of their contribution.