Design-build (DB) is a project delivery model in which the owner holds one contract with a single design-build entity that takes responsibility for both the design and the construction of the facility. That single contract — and the single point of accountability it creates — is the defining feature that distinguishes DB from design-bid-build (DBB), where the owner holds two separate contracts (designer and contractor) and sits in the gap between them. This article defines the model, explains how it actually works mechanically, and maps the principal variants used on US healthcare projects: design-build done direct, bridging (design criteria) design-build, and progressive design-build (PDB).

Design-build collapses design and construction into one contract

In DB, the owner runs a single procurement and signs a single agreement. Behind that agreement, the design-build entity organizes the designers and constructors however it sees fit. Three common organizational forms exist:

• Contractor-led DB — a general contractor (or construction manager) holds the prime contract and engages the architect/engineer (A/E) as a subconsultant or design partner. This is the most common form in US healthcare.
• Designer-led DB — the A/E firm holds the prime and subcontracts construction. Less common; typically appears where design complexity dominates.
• Integrated DB / joint venture — contractor and designer form a single legal entity (an LLC or formal JV) that holds the prime, sharing risk and reward. Used on large, complex programs.
• Developer-led DB — a developer entity wraps design and construction (and sometimes financing) and delivers a turnkey facility. Common where the owner wants to offload program risk, e.g., medical office buildings (MOBs) and some ambulatory developments.

Regardless of internal form, the owner's experience is the same: one entity is accountable for delivering a facility that meets the contract criteria. If a building element doesn't perform, the owner does not have to adjudicate whether the cause was a design defect or a construction defect — that allocation is the design-builder's problem, not the owner's. This collapse of the "design vs. means-and-methods" finger-pointing seam is the central value proposition of DB.

Single-point accountability is the core value proposition

In DBB, the owner sits at the apex of two contracts and inherits the gap between them. When a wall assembly fails an acoustic or infection-control performance target, the designer says the contractor built it wrong and the contractor says the design was deficient — and the owner, who has a contract with each, often ends up absorbing the cost and schedule consequences of resolving it. DB removes that seam:

• Coordination risk shifts to the design-builder. Errors-and-omissions exposure, constructability conflicts, and interdisciplinary coordination (architectural, structural, MEP, medical equipment, low-voltage) are internal to the design-build entity.
• Warranty and defect liability run to one party. The owner pursues a single entity for performance shortfalls.
• Schedule responsibility is unified. The same party controls both the pace of design and the pace of construction, so it cannot blame the other half of the project for delay.

The trade-off — covered in depth in the sibling Articles — is that the owner cedes a degree of direct control over the design. The A/E's primary contractual loyalty runs to the design-builder, not to the owner, which is a meaningful shift in healthcare where clinical users, infection control, and facilities engineering expect deep, iterative design influence. Bridging and progressive DB (below) are largely responses to that concern.

Overlapping design and construction enables fast-track schedule compression

Because one entity controls both phases, DB permits overlapping (concurrent) design and construction — often called fast-tracking. Foundations and structure can be released for construction while interior fit-out, MEP, and specialty clinical spaces are still being designed. This is the primary reason owners on schedule-driven healthcare projects choose DB.

Practical mechanics:

• Phased / packaged permitting and procurement. Design is released in packages (e.g., site/civil, structure, building envelope, interiors) so that early scopes can be bought out and built while later scopes mature.
• Early procurement of long-lead items. Switchgear, generators (NFPA 110 essential electrical system equipment), air-handling units, chillers, medical imaging equipment, and modular components can be ordered before the full design is complete — often the single largest schedule lever on a hospital project.
• Compressed overall duration relative to the strictly sequential DBB path (design fully complete → bid → build). Fast-tracking does not reduce the total work; it parallelizes it.