The answer
Design-Build (Single Contract): One firm provides architectural design and construction under a single contract. Benefits: unified accountability, faster project delivery (overlapping design/procurement), and continuous real-time cost-estimating during design to prevent budget blowouts. Architect + General Contractor (Design-Bid-Build, Two Contracts): Separate contracts with an architect (designs plans) and general contractor (bids/builds). Benefits: independent third-party architectural oversight during construction. Considerations: slower linear timeline and potential schedule/cost friction if constructability discrepancies arise between architect and builder.
Sources
This answer is drawn from the standards and guidance below. It is general information about how these systems work — not a diagnosis of your property.