On August 28, 2026, Missouri’s public contracting landscape changes in an important way. Revised § 67.5060, RSMo., now expressly authorizes political subdivisions to use progressive design-build (“PDB”), while also expanding traditional design-build by reducing the threshold for noncivil projects from $7 million to $2.5 million. The new law gives public owners a two-stage, qualifications-based path for selecting a design-builder and then working collaboratively through the preconstruction phase to develop the design, scope, schedule, and ultimately a fixed price or guaranteed maximum price (“GMP”). The new PDB provisions are presently scheduled to remain in effect through August 28, 2036, as a “test run” period, like the prior design-build statute was (which has now had its “sunsetting” provision removed).
For Missouri contractors, architects, engineers and public owners, the statute creates real opportunity. It also creates a new category of contract risk.
The defining feature of PDB is that construction price is not part of the initial selection process. Instead, in a two-step process, shortlisted teams are evaluated on qualifications and their approach to design development, collaboration, estimating, scheduling, value engineering, subcontractor participation, transparent pricing, innovation, and risk management. Only after selection does the owner negotiate a preconstruction agreement with the highest-ranked team. The parties then “progress” the project to a sufficient level of design development to establish the fixed price or GMP and, if agreement is reached, amend the contract to authorize construction. Of course, the public owner also has the ability to “opt out” at that point.
That is not simply traditional design-build with the price moved to a later date. It requires a different contracting philosophy. Indeed, the Design-Build Institute of America (“DBIA”) released PDB-specific best practices in 2026 because the method presents procurement, contracting and execution issues that are distinct from traditional best-value design-build.
Missouri already has a compelling example. Kansas City International Airport’s (“KCI”) new single terminal and garage, delivered using progressive design-build, became the largest infrastructure project in Kansas City history. DBIA recognized it as its 2025 “Project of the Year” and Best in Process for Progressive Design-Build. The project was delivered approximately 60 days early and $45 million under budget. More important than the awards are the practices behind the result: continual cost validation, early trade-contractor involvement, progressive release of work packages, extensive constructability input and rapid decision-making.
The lesson for the Missouri market is straightforward: PDB can work extremely well, but the contract has to create the machinery that makes collaboration possible.
The Preconstruction Agreement Is the Real Contract
One of the first mistakes parties can make is treating the preconstruction agreement as a short preliminary document to be replaced later by the “real” construction contract. In PDB, many of the decisions that determine whether the project succeeds are made before the GMP exists.
The preconstruction agreement should identify specific deliverables and decision points: design milestones, estimating intervals, schedule updates, constructability reviews, value-engineering studies, risk-register updates, procurement plans, long-lead decisions, and the process for reconciling design to budget. It should also state who has authority to make decisions and how quickly those decisions must be made.
KCI demonstrates why this matters. The team used frequent cost projections and multiple design iterations, with construction review and cost modeling accompanying the developing design. A designated conflict-resolution group helped address disagreements quickly. PDB cannot deliver its intended benefits if an owner needs weeks to answer design questions or every budget issue gets pushed through several layers of bureaucracy.
Define “Open Book” Before Someone Opens the Book
Missouri’s statute expressly identifies “transparent pricing” as a subject that may be evaluated during procurement. That phrase should not be left undefined after award.
The parties should agree at the beginning on the anatomy of the eventual GMP: allowable direct costs, general conditions, home-office overhead, design fees, design-builder fee, insurance, bonds, escalation, allowances, contingency, self-performed work and subcontractor costs. They should also determine what records the owner may review, how subcontractors will be procured, how self-performed work will be validated, and whether an independent cost estimator will be used.
A 2025 National Academies study of open-book pricing practices in CM/GC and PDB projects found that transparency works best when parties establish a common cost model and resolve markups and indirect-cost treatment early. Public agencies also use independent estimates and predetermined reconciliation thresholds as checks on negotiated pricing.
That protects both sides. The owner needs confidence that a post-selection GMP reflects the market. The design-builder needs a process that prevents GMP negotiations from becoming an endless demand to reduce costs without corresponding scope or risk adjustments.
Turn Contingency into a Risk Register
“Contingency” may be one of the most dangerous words in a PDB contract because different participants may mean completely different things by it.
The better approach is to identify risks individually. Who owns geotechnical uncertainty? Utility conflicts? Permitting delay? Material escalation? Unresolved owner criteria? Hazardous materials? Long-lead procurement? Third-party approvals? There are likely many more questions like this, which past experience tells us will come up on projects.
For each major risk, identify the risk owner, mitigation plan, estimated cost exposure, trigger for use of contingency, and what happens to unused contingency when the risk retires.
Public agencies already use different models. Some maintain separate owner and contractor contingencies; others use risk registers with specifically identified risks, costs, triggers and mitigation measures. National Academies research also notes that line-item risk contingencies can permit funds to be retired or reallocated as specific uncertainties disappear.
The broader contracting principle is equally important: risk should be placed with the party best able to evaluate, control or mitigate it. PDB should be an opportunity to price risk intelligently—not simply another vehicle for pushing every unknown downstream.
Design the Off-Ramp Before You Need It
The most important PDB clause may be the provision everyone hopes never to use.
Missouri’s statute tells us what happens if the parties agree on price: they may amend the contract and authorize construction. It does not comprehensively answer what happens after months of design and preconstruction if they cannot reach an acceptable GMP.
That “off-ramp” must be drafted at the beginning.
The agreement should address payment for completed services, termination costs, ownership and licensing of design documents, BIM and electronic models, continuing access to the designer of record, use of subcontractor pricing, confidentiality and transition assistance. It should determine whether the owner may take the partially completed design to another contractor and, if so, what protections the original design-builder and designer receive if that design is later changed or completed by others.
This is not theoretical. National Academies research recognizes that the off-ramp is more complicated in PDB than CM/GC because the design contract sits with the design-builder. Some states address that problem through mechanisms that can permit the owner to retain the designer after an off-ramp. Recent research examining projects where off-ramps were actually exercised likewise found that independent estimating and open-book information helped owners determine whether proposed pricing was reasonable and improved the technical information available for reprocurement.
An off-ramp should therefore be viewed as a project-protection mechanism rather than an admission that PDB failed. The drafting objective is to make it sufficiently clear that neither side becomes economically trapped simply because substantial design work has already occurred.
Early Work Packages Need Their Own Risk Allocation
One of PDB’s greatest advantages is the ability to begin selected work before final design and GMP completion. It is also an area where contracts can become dangerously casual.
The AIA’s 2024 progressive design-build documents (including A141PDB-2024) expressly recognize early release work such as demolition, site work, long-lead procurement and structural steel. Each early package should define its scope, price, schedule, design assumptions, insurance and bonding, ownership of procured materials, cancellation exposure and interfaces with the unfinished design. The parties should also address what happens to that package if the overall project never reaches GMP.
KCI illustrates the upside. Critical trades were engaged during design, shop drawings progressed in parallel with design development, and foundation, steel and curtain-wall packages were released progressively. That helped the team address labor constraints and long-lead procurement while preserving schedule. But acceleration only works when design responsibility and package interfaces are carefully managed.
Protect the Design Professional’s Standard of Care
PDB integrates designer and contractor more tightly, but it does not erase the distinction between construction obligations and professional services.
The design-builder may promise a GMP, completion date, and construction performance. The architect or engineer ordinarily performs under a professional standard of care. Those obligations should not be collapsed through careless flow-down language.
Design-builder agreements with architects and engineers should distinguish design negligence from normal design development, define design-to-budget responsibilities, address reliance on contractor estimates and owner decisions, and carefully coordinate indemnity, limitation-of-liability and insurance provisions.
The contractor’s promise to deliver the project within a GMP should not automatically become a professional warranty that the designer can neither insure nor realistically perform.
Missouri’s statute itself recognizes that distinction by providing that the design-builder’s performance bond does not cover damages of the type designated for professional liability insurance. Teams should therefore examine professional liability, pollution, builder’s risk, CGL, cyber and project-specific coverage before work begins, not after a claim identifies the gaps.
Collaboration Must Be Contractual, Not Aspirational
The greatest misconception about progressive design-build is that “collaboration” can substitute for careful contracting. In reality, the opposite is true.
The more collaborative the delivery model, the more important it becomes to define how decisions are made, costs are validated, risks are retired, and disagreements are escalated. Strong PDB agreements contain mechanisms that keep disputes from becoming project events: executive escalation, mandatory meet-and-confer procedures, project neutrals or dispute-review processes, defined decision deadlines and contemporaneous documentation of assumptions.
Recent revisions to industry contract forms recognize exactly that problem, including procedures that move disputes quickly to authorized business representatives or a project neutral rather than allowing disagreements to linger while the project proceeds.
The KCI experience proves the potential. Its success was not simply the product of goodwill. It resulted from integrated teams, clear goals, repeated cost and constructability review, early specialty-trade participation, flexible procurement and a willingness to resolve problems while they could still be solved.
The Takeaway for Missouri
Progressive design-build should be a major improvement in Missouri public contracting because it allows owners to select teams based on capability and then price construction after the project is better understood. Used correctly, it can replace hidden contingency with visible risk analysis, late constructability problems with early trade input, and adversarial change-order positioning with joint problem-solving.
But PDB does not eliminate construction risk. It moves important risk decisions earlier.
For Missouri owners, contractors, and design professionals preparing for the new statute, the practical advice is straightforward:
- Define the cost model before GMP negotiations begin.
- Develop and continuously maintain a project-specific risk register.
- Separate owner contingency from design-builder contingency where appropriate and establish rules for their use.
- Create objective procedures for validating subcontractor pricing, self-performed work, and the evolving estimate.
- Consider an independent cost estimator on larger or more complex public projects.
- Draft the off-ramp before substantial design expenditures occur.
- Treat every early-release package as a real construction contract with its own risk allocation.
- Protect the architect’s and engineer’s professional standard of care from inappropriate GMP, warranty and schedule flow-down obligations.
- Align the owner/design-builder agreement with the design and major trade agreements rather than negotiating those contracts in isolation.
- Create an expedited decision and dispute-escalation structure capable of resolving problems while they remain manageable.
Progressive design-build works best when the parties do not merely agree to collaborate. They agree, in advance, on exactly how collaboration will work when the project becomes difficult.
That may ultimately be the most important lesson for Missouri’s construction industry as the new statute takes effect. The opportunity created by progressive design-build is not simply the ability to postpone the construction price. It is the ability to use the period before that price is established to identify uncertainty, allocate it intelligently, involve the people who can solve it, and write a contract that reflects what the parties actually know rather than what they were forced to assume at bid time.