Design-Build Delivery for Marine Infrastructure: Reducing Risk and Improving Outcomes for Complex Waterfront Projects

Marine infrastructure - including navigation structures, bulkheads, wharves, piers, and guide walls - is essential to economic activity and national logistics networks. Many of these assets are aging and require rehabilitation or replacement under increasingly constrained budgets and demanding operational conditions.

Marine construction projects are commonly performed in environments with limited accessibility and continuous exposure to hydraulic, environmental, and operational forces. Construction activities must frequently occur within restricted environmental windows, active navigation corridors, and around structures that remain in service throughout the work. These realities demand a project delivery approach that is inherently adaptive, collaborative, and risk-aware.

Traditional Design-Bid-Build (DBB) delivery methods require completion of design prior to contractor involvement, creating a fundamental disconnect between design assumptions and construction realities. In contrast, Design-Build (DB) delivery integrates these functions under a single entity, enabling more responsive and efficient project execution.

This article examines the application of design-build delivery in marine construction, focusing on its ability to reduce risk, improve constructability, and deliver better outcomes for infrastructure owners navigating complex waterfront projects.

​Background and Industry Context
Characteristics of Marine Construction
Marine construction projects present several defining characteristics that distinguish them from land-based work:

• Limited access: Work is performed from barges, temporary platforms, or underwater, reducing efficiency and increasing complexity. Equipment mobilization and material handling require specialized marine plant and careful logistical planning.
• Environmental constraints: Tides, river stages, currents, wave action, and weather significantly influence construction operations and can halt work for extended periods.
• Operational constraints: Many projects occur adjacent to active navigation channels or operational port and terminal facilities, requiring careful coordination to avoid disruptions to commerce and vessel traffic.
• Inspection limitations: Underwater visibility and access restrict the accuracy of pre-design condition assessments. Submerged elements are often difficult to evaluate comprehensively, even with underwater inspection and underwater acoustic imaging.

These factors contribute to a high likelihood of encountering unforeseen conditions during construction which can fundamentally alter the scope, cost, and schedule of a project if the delivery method lacks the flexibility to respond.

Limitations of Design-Bid-Build Delivery
The Design-Bid-Build model separates design and construction into sequential, contractually distinct phases. While widely used and well understood, this approach introduces several limitations that are amplified in the marine environment:

• Limited incorporation of contractor expertise during design: The contractor is not engaged until after design is complete, meaning practical construction knowledge - particularly regarding means and methods - is absent from critical design decisions.
• Fragmented risk allocation: Responsibility is divided between the designer and the contractor, often leading to ambiguity when unforeseen conditions arise. The owner frequently bears the burden of resolving disputes between the two parties.
• Increased potential for change orders and claims: When underwater conditions differ from design assumptions - a common occurrence in marine work - the result is often redesign, procurement delays, and contract modifications that drive up costs and extend schedules.
• Coordination burden on the owner: The owner must manage multiple contracts, schedules, submittals, and lines of communication across separate firms, adding administrative complexity and risk.

In marine construction, where unknowns below the waterline are the rule rather than the exception, these limitations can transform manageable projects into contentious, over-budget endeavors.

The Design-Build Delivery Framework
Design-build delivery consolidates design and construction responsibilities within a single entity, fundamentally changing the dynamics of project execution. This integration allows for:

• Early integration of construction methods into design: The builder's knowledge of means, methods, and equipment informs the design from the outset, producing documents that are inherently more constructable.
• Continuous feedback between field conditions and engineering decisions: As conditions are revealed during construction - particularly underwater - the design team can adapt in real time without the delays of formal change order processes between separate organizations.
• Overlapping design and construction activities: Design-build enables fast-tracking, where construction on well-defined elements can proceed while design continues on others, compressing the overall project timeline.
• Unified responsibility for risk management: A single entity owns the outcome from investigation through project closeout, eliminating finger-pointing and creating a natural incentive to identify and mitigate risks proactively.

This integrated approach is particularly well suited to marine construction, where adaptability, constructability, and rapid decision-making are not luxuries - they are necessities.

Advantages of Design-Build for Infrastructure Owners
Risk Allocation and Management
One of the most significant advantages of design-build is its ability to align risk with the party best equipped to manage it. In marine construction, key risks include:

• Underwater uncertainty: Submerged conditions are inherently difficult to characterize fully before construction begins. Design-build allows the team to adapt designs as actual conditions are revealed, rather than forcing the owner to negotiate change orders between separate firms.
• Constructability challenges: Marine work involves specialized equipment, environmental work windows, and complex sequencing. When the entity responsible for design is also responsible for construction, designs naturally account for these realities.
• Means and methods selection: The design-build team can select and optimize construction approaches based on integrated engineering and field knowledge, rather than having a contractor attempt to execute a design developed without their input.

By consolidating responsibility, design-build reduces the potential for disputes and encourages proactive risk mitigation. The owner benefits from a single point of accountability - one contract, one schedule, and one team responsible for delivering the project.

Constructability and Innovation
Early contractor involvement is a hallmark of design-build, and it produces designs that reflect actual construction conditions rather than theoretical assumptions. This integration fosters innovation that is difficult to achieve under traditional delivery:

• Modular and precast solutions: Design-build teams frequently leverage prefabricated elements - such as precast concrete blocks or modular structural components - that can be manufactured offsite and assembled in the water. This approach reduces reliance on difficult and time-consuming in-water construction, simplifies installation, and improves quality control.
• Optimized construction sequencing: The integrated team can design the project around the most efficient construction sequence, accounting for environmental windows, equipment capabilities, and site access constraints from the start.
• Improved durability and maintainability: When the builder participates in design, practical considerations like long-term maintenance access, material durability in the marine environment, and resilience against future impacts (such as vessel strikes) are incorporated from the beginning.

These types of innovative, practical solutions are far less likely to emerge under traditional delivery methods, where the designer and contractor operate in isolation.

Schedule and Cost Benefits
Design-build facilitates meaningful schedule compression and cost control through several mechanisms:

Schedule advantages:

• Parallel execution of design and construction activities, rather than sequential phasing
• Early procurement of long-lead materials and specialized equipment
• Reduced delays associated with redesign when field conditions differ from assumptions
• Elimination of the re-mobilization gaps that occur when transitioning between separate design and construction contracts

Cost advantages:

• Fewer change orders, as constructability issues are resolved during design rather than discovered during construction
• Improved construction efficiency through designs optimized for the builder's equipment and methods
• Reduced overall project duration, which lowers time-dependent costs such as equipment rental, marine plant, and environmental monitoring
• Real-time constructability input during design allows pricing to be validated before documents are finalized, reducing the contingencies that contractors build into bids under traditional delivery

Industry experience consistently demonstrates that in-water construction can take two or more times longer than equivalent out-of-water work. Design-build teams, by integrating this knowledge into the design process, can maximize offsite fabrication and minimize the duration of the most difficult and expensive construction activities.

Operational Continuity
For infrastructure owners, minimizing disruption to ongoing operations is often as important as the construction itself. Navigation channels must remain open, terminals must continue to function, and adjacent facilities must be protected. Design-build supports operational continuity through:

• Phased construction approaches: The integrated team can design and sequence the work to maintain operations throughout construction, completing the project in stages that minimize closures and restrictions.
• Reduced interference with navigation or terminal operations: By optimizing construction methods and schedules around operational demands, design-build minimizes the impact on vessel traffic and commercial activity.
• Greater flexibility in responding to operational constraints: When unexpected operational needs arise - such as emergency vessel movements or seasonal traffic surges - the design-build team can adapt the construction schedule and approach without the contractual friction inherent in multi-party delivery.

Simplified Owner Experience
Beyond the technical and financial advantages, design-build fundamentally simplifies the owner's role in project delivery:

• Single point of contact: The owner manages one relationship, one contract, and one schedule, rather than coordinating between multiple firms with potentially competing interests.
• Reduced administrative burden: Submittals, RFIs, schedule updates, and progress reporting flow through a single entity, streamlining communication and decision-making.
• Faster issue resolution: When problems arise the design-build team resolves them internally rather than generating claims and disputes that the owner must adjudicate.

Conclusion
Marine construction projects are inherently uncertain and complex, requiring delivery methods that can adapt to changing conditions in real time. Traditional design-bid-build approaches, while familiar and widely used, are often poorly suited to these environments due to their inherent fragmentation, rigid sequencing, and limited flexibility.
Design-build delivery provides a more effective framework by integrating investigation, design, and construction into a single, cohesive process. This integration enables:

• Improved risk management through unified responsibility and proactive mitigation
• Enhanced constructability through early and continuous builder involvement in design
• Accelerated project delivery through parallel activities and reduced rework
• Reduced cost growth through fewer change orders and optimized construction methods
• Greater operational continuity through flexible, phased construction approaches

For complex marine infrastructure projects design-build should be considered the preferred delivery method. Its integrated approach directly addresses the unique challenges of the marine environment and delivers measurably better outcomes for infrastructure owners.

Recommendations for Infrastructure Owners
To maximize the benefits of design-build in marine construction, infrastructure owners should consider the following best practices:

1. Develop clear, performance-based project requirements. Define the desired outcomes and performance criteria rather than prescribing specific designs or methods. This gives the design-build team the flexibility to innovate and optimize.
2. Prioritize qualifications and technical expertise in procurement. Select design-build teams based on demonstrated experience in marine construction, engineering capability, and a proven track record of integrated delivery - not solely on low price.
3. Allow flexibility for innovation and alternative technical approaches. Encourage proposers to offer creative solutions that leverage their combined design and construction expertise. The best outcomes emerge when teams are empowered to solve problems, not just follow prescriptive specifications.
4. Encourage early and thorough field investigation. Invest in comprehensive pre-design data collection - including structural inspections above and below water, geotechnical sampling, bathymetric surveys, and material testing. The more that is known before design begins, the fewer surprises will arise during construction.
5. Align contract structures to support adaptive decision-making. Marine projects will encounter unforeseen conditions. Contract terms should facilitate rapid, collaborative responses rather than adversarial change order negotiations. Structures that allow for adaptive decision-making - such as allowances for differing site conditions and mechanisms for real-time scope adjustments - produce better project outcomes for all parties.

Design-build delivery represents a fundamental shift in how marine infrastructure projects are planned, designed, and constructed. Unifying these traditionally separate functions creates a delivery framework that is better aligned with the realities of working on and under the water where adaptability, collaboration, and integrated expertise are the keys to success.

​Author: Bradley A. Syler, PE, SE