Why Design & Build Contracts Keep Failing Mission-Critical Facilities

Reviewed by Yoan Guyon, Managing Director at gbc engineers

Design & build contracts sell owners a simple promise: one contract, one point of accountability, faster delivery. For a warehouse or a mid-rise office, that trade works well. 

For a data center, hospital or semiconductor fab, the same trade quietly creates risk that never shows up in the bid comparison. These are mission-critical facilities. That means buildings that cannot go down without serious consequences, whether that means medical care interrupted or cloud services offline. 

The risk is structural, not personal. Design & build puts design and construction under one firm, and that firm has its own financial incentive to cut costs. 

Why owners keep choosing design & build now

3 forces are pushing mission-critical construction into its biggest building boom yet. AI is driving a surge in data center construction. Semiconductors are coming back onshore. Healthcare is expanding capacity fast. 

Owners under pressure to move quickly lean on design & build because it compresses the time between decision and delivery. But design & build was built for projects that can tolerate "good enough." Mission-critical facilities cannot. 

A data hall that is 90% right on redundancy is not 90% functional. It has a single point of failure. That gap usually surfaces during commissioning, or worse, after the facility is already running. 

McKinsey projects data center capital investment will reach USD 6.7 trillion globally by 2030, more than Japan's entire annual economic output. Pushing that much money through the wrong delivery model turns occasional failures into a routine pattern. 

Read more: Sustainable Data Centers: What are they and How they work

Where the design & build model actually breaks

The contract structure shifts who makes technical decisions. On a mission-critical facility, that shift shows up in a few consistent places. 

• Compromised redundancy architecture. Fixed-price contracts create a direct incentive to swap reliable systems for cheaper equivalents. 
• Vendor-driven decisions. A design & build firm tends to use the supply chain it already knows, not necessarily the specification that fits the owner's needs. 
• Fragmented specialist oversight. Design & build firms typically subcontract MEP scope out, so clashes between systems surface late instead of during design. 
• Diluted access to the people who know the building. The engineers who understand redundancy logic become harder to reach. 
• Weak commissioning under schedule pressure. A firm that manages its own commissioning has every reason to rush that check to meet handover deadlines. 

Read more: Data Center Water Use: Sustainable Cooling Design

How does risk shift across delivery methods?

Moving from design & build toward CMAR changes who owns technical decisions. It also changes how early a problem gets caught. The table below shows how much the risk shifts.

How design-bid-build and CMAR reduce delivery risk

Experienced owners respond by putting independent technical oversight back into the process before construction starts: 

• Design-bid-build. The owner's own engineers fully develop the design first, so contractors bid on precise specifications. 
• Construction Manager at Risk (CMAR). A construction manager joins early for pricing input, but design decisions stay with the owner's team. 
• Independent third-party commissioning. A commissioning agent who reports to the owner reliably catches missing backups before a facility goes live. 
• Third-party engineering consultants. Some owners bring in outside consultants for an independent design review. 

Read more: Why data center construction projects go over budget 

Conclusion

Design & build is not disappearing from mission-critical construction, and it should not. Where requirements are well understood and stable, it still delivers speed that owners value.  The real shift is in where sophisticated owners draw the line. Facilities that cannot tolerate failure move toward design-bid-build or CMAR instead. 

Frequently asked questions

What is the main problem with design & build contracts for data centers?

Design & build combines design and construction under one commercially incentivized firm. That removes the independent checks that normally catch redundancy gaps before they get expensive. 

Is design & build always the wrong choice for mission-critical facilities?

Not always. It works well when requirements are stable and well understood. The risk rises on facilities with tight redundancy needs. 

What is the difference between design & build and design-bid-build?

In design & build, one firm holds both design and construction responsibility. In design-bid-build, the owner's independent engineers develop the design first, then contractors bid on those fixed specifications. 

What is Construction Manager at Risk (CMAR), and how is it different from design & build?

CMAR keeps a construction manager involved early for cost input, but design authority stays with the owner's independent team. 

Why does commissioning matter so much on mission-critical projects?

Because it is the last check that a facility performs as designed under real failure scenarios. A firm that manages its own commissioning has every reason to shorten that check under schedule pressure. 

Does the delivery method affect insurance or warranty risk?

Yes, indirectly. When technical decisions shift to a single contractor, any resulting shortfall is harder to trace back to a specific design choice.