27 Aug Design-Build vs. Design-Bid-Build: Which Delivery Method Is Right for Your Nashville Project?
The right project delivery method depends on your schedule, budget certainty, and how much design control your organization needs before construction begins.
Why It Matters
Project delivery method — the contractual and organizational structure used to design and build a facility — directly affects cost, schedule, risk allocation, and owner involvement. Choosing the wrong method can result in budget overruns, extended timelines, or disputes between designers and contractors that delay occupancy.
In Middle Tennessee’s active commercial construction market, owners across healthcare, corporate real estate, and institutional sectors face this decision regularly. Understanding the structural differences between Design-Build and Design-Bid-Build (also called traditional delivery) helps owners align their procurement strategy with their project goals before any contracts are signed.
How It Works
In the Design-Bid-Build (DBB) model, an owner first hires an architect or engineer to complete a full set of construction documents. Once those documents are finalized, the project is put out to competitive bid, and a general contractor is selected — typically based on price. The three parties (owner, designer, contractor) operate under separate contracts, meaning the contractor has no input during design.
In the Design-Build (DB) model, a single entity — either a contractor-led team or a joint venture — is responsible for both design and construction under one contract. The owner negotiates with one party, and the design and construction phases overlap, which can compress the overall project schedule. This integrated approach shifts more coordination responsibility to the Design-Build team and reduces the owner’s role in managing design-contractor conflicts.
A common financial structure in Design-Build contracts is the Guaranteed Maximum Price (GMP), a contract ceiling that defines the maximum the owner will pay, with any savings typically shared between owner and contractor according to a pre-negotiated formula. DBB projects may also use GMP contracts, but the competitive bid process more commonly yields lump-sum pricing after design is complete.
What the Data Says
According to the Design-Build Institute of America (DBIA), Design-Build projects are delivered 102% faster than Design-Bid-Build projects and cost approximately 6.1% less per square foot when compared on a unit-cost basis. These figures are based on a Federal Highway Administration study across public sector projects, though comparable trends have been observed in private commercial construction.
Design-Bid-Build, however, remains the preferred method when owner organizations require full design completion before committing to construction funding — common in institutional or publicly funded projects in Tennessee where procurement regulations or board approvals govern spending. The additional design time in DBB can also reduce construction-phase change orders (modifications to the contract scope after construction begins), which are a primary driver of cost growth on fast-track projects.
Key Considerations
Owners evaluating delivery methods should weigh four primary factors: schedule flexibility, design control, risk tolerance, and internal project management capacity. Design-Build is generally more appropriate when the schedule is compressed, the program (the written description of a building’s functional requirements) is well-defined, and the owner has limited staff to coordinate between separate design and construction contracts.
Design-Bid-Build is typically the better choice when an owner wants maximum competitive pricing through open bidding, requires a highly customized or technically complex design, or operates under procurement rules that mandate separation of design and construction services. In Nashville’s healthcare construction sector, for example, regulatory requirements and phased occupancy needs often influence which delivery model is operationally feasible. As shown in the company’s project portfolio at https://consecogroup.com/projects/, both delivery approaches have been applied across different commercial building types depending on project-specific constraints.
Hybrid models also exist. Construction Manager at Risk (CMAR) — a structure where a construction manager is hired early to provide preconstruction services and then assumes financial risk for delivery — shares characteristics of both methods. It offers early contractor involvement (similar to Design-Build) while preserving separate design and construction contracts (similar to DBB). The CMAR model is increasingly used for complex institutional projects in Middle Tennessee where phased construction and operational continuity are priorities. The firm’s services framework, outlined in the services overview at https://consecogroup.com/, reflects how delivery method selection integrates with preconstruction planning.
What is the main difference between Design-Build and Design-Bid-Build?
Design-Build combines design and construction responsibility under a single contract with one entity, while Design-Bid-Build uses separate contracts for the designer and contractor, with the construction bid occurring only after design documents are fully completed. The key practical difference is that Design-Build allows design and construction to overlap in schedule, whereas Design-Bid-Build requires sequential completion of each phase before the next begins.
Which delivery method is faster?
Design-Build is generally faster because design and construction activities can run concurrently rather than sequentially. Research from the Design-Build Institute of America indicates Design-Build projects are completed measurably faster than comparable Design-Bid-Build projects, primarily because early contractor involvement allows long-lead procurement and site preparation to begin before design is fully finalized.
Which method gives the owner more design control?
Design-Bid-Build typically gives the owner more direct control over design decisions because the owner holds a separate contract with the architect and reviews and approves completed design documents before construction begins. In Design-Build, the design process is managed largely by the Design-Build entity, which means owners must clearly communicate their program requirements upfront and rely on contract language to enforce design standards.
Is Design-Build appropriate for healthcare or regulated facilities in Tennessee?
Design-Build can be used for healthcare and regulated facilities in Tennessee, but it requires careful contract structuring to address Tennessee Department of Health plan review requirements, infection control protocols, and phased occupancy conditions. Many healthcare owners in Middle Tennessee opt for the Construction Manager at Risk model because it retains the benefit of early contractor involvement while preserving the owner’s direct relationship with the architect of record.
How do I start evaluating which delivery method fits my project?
Owners typically begin by assessing schedule urgency, budget certainty requirements, internal project management capacity, and whether the project scope is well-defined before design begins. Engaging a construction manager during the preconstruction phase — before selecting a delivery model — allows for a structured analysis of which approach aligns with the project’s risk profile and operational constraints. Project teams seeking structured guidance on this decision can reach the firm directly through the contact page listed on the firm’s contact page at https://consecogroup.com/contact/.
Conseco Group, a Nashville-based CM/GC founded in 1987, applies these practices across healthcare, office, and industrial projects.