The construction industry relies on various project delivery models to manage complexity, allocate risk, and optimize financial arrangements. These models define relationships between owners, contractors, designers, and financiers, significantly impacting project outcomes. Below is an in-depth exploration of key construction delivery models, their benefits, challenges, and best-use scenarios.
1. Design-Bid-Build (DBB)
Description
- The DBB is a traditional procurement option in which the Owner awards two distinct and sequential contracts for the design and construction work:
- The first contract is with a design firm to develop a full detailed design and to assist the Owner in putting the construction of the project out to tender; and
The second contract is with a general contractor to build that design
- Under this model, the operations, maintenance and financing of the project would remain the responsibility of the Owner
Most suitable for: Lower complexity projects with less room for private sector innovation. Projects requiring high degree of Owner control
Best for: Simple building projects such as small commercial buildings, schools, and government facilities requiring strict owner oversight.
Risk Allocation
The project Owner retains the majority of the project risks (e.g., cost/schedule overruns) and has to manage the interface with the design firm, who may claim defective construction, and the general contractor, who may claim faulty design
Benefits
- Increased Control–Significant degree of Owner control over the project by managing the design and construction and separate contracts
- Significant Market Experience–Well understood and commonly used approach
- Flexibility–Flexibility to respond to changing conditions and citizen concerns
Challenges
- Lacks Integration –Requires completed design before awarding construction contract
- Minimal Risk Transfer–Owner retains majority of the project risks (e.g., cost/schedule overruns)
- Less Opportunity for Innovation–Less opportunity for private sector to create efficiencies during the operations period than DBF(O)M and concession models.
Construction Impact: Ensures clear accountability for design and construction but can result in inefficiencies and project delays due to the sequential process.
2. Build-Finance (BF)
Description
- Similar to the DBB in the sense that the Owner hires separate contractors for the design and construction work
- The Owner hires and oversees an engineering firm to complete the project design based on planning specifications and assumes responsibility for that design which is the basis for the BF bid
- The contractor constructs the project following the Owner’s design and specifications and is able to raise financing because of its ability to perform its obligations under the contract
- The contractor is paid upon construction completion instead of construction progress payments
Most suitable for: Lower complexity projects with less room for private sector innovation. Projects with limited design and construction collaboration efficiencies and scope not expected to materially change during the construction period
Risk Allocation
- Improved risk allocation vs. the DBB model as cost overrun risk is transferred to the private sector
Benefits
Cost and Schedule Certainty–Provides the Owner cost and schedule certainty around the delivery of the project. Cost overruns are backstopped by third-party financing and significant financial penalties in the event of a delay to substantial completion
Significant Market Experience–Well understood and commonly used approach
Challenges
Lacks Integration –Requires completed design before awarding construction contract
Less Flexible than DBB–Higher cost for design changes that are retained by the Owner due to the added financing component and associated lenders’ consent
Best for: Infrastructure projects with predictable scope, such as road expansions and utility upgrades.
Key Benefits: Improved cost certainty, reduced owner risk.
Challenges: Higher cost for design changes, limited flexibility.
Construction Impact: Encourages financial discipline but limits contractor flexibility during execution.
3. Design-Build (DB) / Engineering, Procurement, and Construction (EPC)
- A single contract for both design and construction, allowing greater integration and efficiency.
- The DB/EPC model awards the design and construction under a single contract based on performance specifications rather than a detailed design
- Consortiums, joint ventures and/or subcontracting arrangements may be established between two or more companies to pool the resources and expertise necessary to deliver a DB project
- Under a DB/EPC contract, the Owner continues to operate, maintain, and refurbish the asset after project delivery. Furthermore, the Owner is responsible for financing the entire project
- the Owner would make milestone payments to the contractor based on the value of work completed hence, the DB consortium does not have to arrange significant amounts of private financing
- Most suitable for: Projects of varying degree of complexity requiring private sector innovation during the design and construction stages
Risk Allocation
Unlike the DBB model, under the DB/EPC approach, the interface risk associated with the design and construction of the project is allocated to the DB consortium
Benefits
- Greater Efficiency and Cost Savings Potential–Integration of design and construction creates efficiencies and cost savings
- Cost and Schedule Certainty–More certainty on final construction price and completion
- Accelerated Delivery Schedule–Can accelerate project delivery schedule
- Reduced Risk–Reduced design and construction risk for the Owner
Challenges
- Lacks a Holistic Lifecycle Approach–Doesn’t optimize lifecycle costs and long-term quality/performance
- Less Opportunity for Innovation– Less opportunity for private sector to create efficiencies during the operations period than DBF(O)M and concession models.
4. Integrated Project Delivery (IPD) / Alliance
- A collaborative approach where all stakeholders share project risks and rewards.
- The fundamental difference between an Integrated Project Delivery (IPD)/Alliance contract and a traditional contract is the underlying principle of a non-adversarial approach between the contracting parties achieved through the establishment of IPD/Alliance principles, good faith commitments, and adoption of no-dispute provisions
- Under this strategy, all parties (owner, designer, construction contractor, suppliers, local organization, community stakeholder, funding organization, etc.)share the responsibility for the entire project, including design, construction, construction management, and risk management
- Most suitable for: Projects with scopes that are difficult to define, have the potential to change substantially over time, risks that are unquantifiable, or require innovative solutions
Risk Allocation
- Design risks and construction cost overruns are shared
- Compensation is directly tied to cost, schedule, and profitability milestones of the project -structured in a way that all parties either win or lose together, incentivizing “best for project” solutions
Benefits
- Common Goals –The primary parties are incentivized to achieve the same set of goals
- Risk Sharing–High degree of risk sharing and may be desirable when risks are difficult to quantify
- Greater Opportunity for Innovation –Collaborative process encourages a greater degree of innovation
- Reduced Threat of Disputes–Integrated governance structure aims to reduce threat of disputes
Challenges
- Behaviour Dependency –Project success is dependent on behaviour of individuals in the team
- Cost & Schedule Risk–Shared under IPD/Alliance contracts, exposing the owner to ‘uncapped risk’
- Less Price Competition –Projects are not competitively bid
- Low Market Experience –Less project experience and lessons learned to draw from
Construction Impact: Enhances coordination, reduces rework, and improves quality but requires strong collaboration and trust.
5. Construction Management at Risk (CM@R)
- The contractor provides consulting services during pre-construction and takes responsibility for construction within a Guaranteed Maximum Price (GMP).
- The CM@R contractor provides consultancy services to the Owner during the pre-construction stage (constructability, tender administration, etc.) and is later contracted to deliver the construction of the project under a cost-plus-fee arrangement i.e., Guaranteed Maximum Price (GMP)
- The GMP is negotiated before the design is fully complete, and the remaining design is then managed by the CM@R contractor within the GMP
- The CM@R contractor is responsible for any construction cost overruns above the GMP
Most suitable for: Relatively complex projects involving multiple phases, complex management of trades etc.
Benefits
- Timely Completion–The CM@R contractor can assist in understanding the complexities in construction and schedule development, encouraging a more efficient construction period and timely completion. GMP encourages timely construction completion
- Enhanced Constructability–Design is reviewed from a constructability perspective
Challenges
- Minimal Schedule Risk Transfer–Risk of schedule delays are retained by the Owner
- Reduced Control-The Owner’s control is reduced during the construction phase as the CM@R contractor has signing authority
- Lower Construction Quality –CM@R contractor is not financially-motivated to ensure construction quality
- Less Opportunity for Innovation–Less opportunity for private sector to create efficiencies during the operations period than DBF(O)M and concession models.
- Reduced owner control, lower construction quality assurance.
Construction Impact: Improves constructability reviews but may lead to higher costs due to risk premiums.
6. Design-Build-Finance (DBF)
Description
- Similar to a DB model, a DBF approach awards the design and construction under a single contract. Consortiums, joint ventures or subcontract agreements may be established between two or more companies to pool the resources and expertise necessary to deliver a DBF project
- The DBF consortium must obtain short-term construction financing from third-party lenders or use its own equity resources with maximum gearing prescribed by the Owner. A lump-sum payment at substantial completion is intended to pay off design and construction costs, and construction financing costs incurred by the DBF consortium
- Most suitable for: Projects with a capital cost of at least $100 million and higher complexity that could benefit from collaboration between designer and constructor and the enhanced diligence from the lender(s)
Risk Allocation
Under a DBF model, responsibility for construction financing and the associated financing risks are transferred to the DBF contractor/consortium.
Benefits
- Greater Cost and Schedule Certainty-No payment to Project Co until substantial completion is achieved (assumes no progress payments)
- Greater Risk Transfer–Reduced design and construction risk for the Owner. Financial risks borne by Project Co (construction period only)
- Greater Efficiencies and Cost Savings Potential-Integration of design and construction creates efficiencies and cost savings
Challenges
Lacks a Holistic Lifecycle Approach-Doesn’t optimize lifecycle costs and long-term quality/performance
No Performance Guarantee-No “guarantee” of asset performance and quality during operations
7. Design-Build-Finance-Maintain (DBFM) & Design-Build-Finance-Operate-Maintain (DBFOM)
- The DBFM model involves Project Co accepting responsibility for the design, construction, financing, regular maintenance and rehabilitation of the asset over the contract term to meet pre-defined performance specifications. The DBFOM model also involves Project Co taking responsibility for operations under the same contract
- The payments over the contract term include:A fixed capital repayment component to repay Project Co’s long-term debt and equity investors for their financing of the construction; and
- For DBFM, a maintenance payment to compensate Project Co for its ongoing maintenance work and major capital rehabilitation (supplemented by an operations payment to compensate for day-to-day operations in case of DBFOM)
Most suitable for: Projects with a capital cost of at least $100 million and higher complexity where both the maintenance and operations have the potential to be transferred to the private sector in case of DBFOM (maintenance only, in case of DBFM)
Risk Allocation
A DBFM approach allows the public sector to allocate significant risks arising during construction, regular maintenance, and lifecycle (rehabilitation) to the private sector. The DBFOM model also involves the transfer of operations risk
Benefits
- Greater Efficiencies and Cost Savings Potential-Integration of design and construction creates efficiencies and cost savings
- Significant Risk Transfer-Significant risk transfer to Project Co over the life of the agreement. Reduced design and construction risk for the Owner. Financial risks borne by Project Co
- Performance Guarantee-Lender discipline to ensure performance is met throughout the agreement and at handback. Performance-based service payments encourages higher maintenance quality
- Encourages a Holistic Lifecycle Approach-Optimizes long-term quality/performance and lifecycle costs. Long term maintenance costs set up front and funding plan put in place
Challenges
- Higher Borrowing Costs-Higher cost of private sector borrowing compared to public sector borrowing
- Less Control-Less direct control and potentially less flexibility during operating period
- Less Flexibility –Potentially less flexibility during operating period
Construction Impact: Ensures long-term asset quality but requires strict contract enforcement to maintain standards.
Conclusion
Each delivery model shapes the way construction projects are executed, influencing efficiency, cost, risk, and long-term asset performance. Selecting the right approach depends on factors such as project complexity, funding mechanisms, stakeholder collaboration, and operational considerations. By choosing the appropriate model, construction professionals can enhance project success, optimize resources, and deliver sustainable infrastructure for the future.