Design-Bid-Build (DBB) rests on two separate, sequential prime contracts held directly by the owner — one with the architect/engineer (A/E) for design, one with the general contractor (GC) for construction — with no contractual link between them. This article describes how those agreements are structured, who carries which risk, and why DBB's separation of design and construction shapes the owner's exposure on a healthcare project.

DBB uses two separate owner-held prime contracts with no privity between designer and builder

The defining contractual feature of DBB is the separation of design and construction into two independent agreements, both held by the owner:

• Owner–A/E agreement — the owner retains an architect (typically with engineering consultants — structural, MEP, low-voltage, medical equipment planning) to produce a complete, biddable, permit-ready set of construction documents. On healthcare work this includes coordination with the code path (FGI Guidelines, IBC, NFPA 101/99, ASHRAE 170, NEC 517) and with the AHJ and any state design-review authority (e.g., HCAI in California, state health-department plan review elsewhere).
• Owner–GC agreement — once design is complete, the owner competitively bids the documents and awards a construction contract to a general contractor, who builds to the finished set.

Critically, the A/E and the GC have no contract with each other (no "privity"). Each answers only to the owner. The owner sits in the middle as the contractual hub and the conduit for all communication between designer and builder. This is the structural root of DBB's risk profile: because the builder did not help shape the documents, gaps or conflicts in those documents become the owner's problem to resolve — usually through a change order and frequently through a dispute over who pays.

Standard industry forms reflect this two-contract shape — for example the AIA A101/A201 family (owner–contractor agreement plus general conditions) paired with the AIA B101 (owner–architect agreement), or the analogous ConsensusDocs and EJCDC families. Healthcare owners commonly amend these heavily (insurance, indemnity, infection-control, ICRA/PCRA obligations, interim life-safety measures, commissioning, and AHJ-coordination language).

Construction is procured at a fixed lump-sum price against complete documents

DBB construction is almost always awarded as a stipulated-sum (lump-sum) contract: the GC commits to a single fixed price to build the documented scope. Because the documents are (in principle) complete and the GC is bound to a hard number, the contractor carries the means-and-methods and price-certainty risk for the defined scope.

Key consequences of the lump-sum structure:

• The owner gets early price certainty — a single competitively bid number before construction starts, which is the model's principal advantage and a common driver for capital approvals and public procurement.
• The contractor owns productivity, sequencing, and trade-coordination risk — if the work takes more labor or more time than the GC estimated, that erosion is the GC's, not the owner's, so long as the scope and documents did not change.
• The owner owns the completeness and accuracy of the documents. Lump-sum pricing only protects the owner for what is actually drawn and specified. Anything missing, ambiguous, or in conflict is outside the bid and re-enters as a change.

Unit-price and (less commonly) cost-plus arrangements exist within DBB for scopes that can't be fully quantified at bid (e.g., unsuitable-soils removal, select demolition, hazmat abatement in an existing hospital), but the core of DBB is the fixed lump sum.

The Spearin doctrine puts design-adequacy risk on the owner

The legal backbone of DBB risk allocation in the US is the Spearin doctrine (from the 1918 US Supreme Court case United States v. Spearin): when an owner furnishes plans and specifications to a contractor, the owner impliedly warrants that those documents are adequate and buildable. The contractor who builds in conformance with owner-provided documents is not liable if the documents themselves are defective.

The practical effect on a DBB project:

• Design errors and omissions flow back to the owner. If the construction documents are wrong or incomplete, the GC is generally entitled to a change order (added cost and time) for the corrective work, because it bid and built what the owner gave it.
• The owner's recourse runs to the A/E, not the GC. Having paid the GC for the fix, the owner may pursue the designer for negligence under the standard of care — a separate, often slower and contested, professional-liability claim against the A/E and its errors-and-omissions (E&O) insurance.
• This two-step recovery is the core friction of DBB. The owner is caught between two parties who have no contract with each other and a built-in incentive to point at one another. The GC says "I built what was drawn"; the A/E says "any competent contractor should have caught/coordinated that." The owner pays first and litigates second.