Choosing the Right Project Delivery Method: Design-Bid-Build vs. CMAR vs. Design-Build
When planning a public infrastructure project, one of the most important early decisions you’ll make is selecting the right project delivery method. This choice impacts your project’s timeline, budget control, collaboration, and overall risk management.
Here’s a breakdown of the three common delivery methods: Design-Bid-Build (DBB), Construction Manager at Risk (CMAR), and Design-Build (DB) — along with when to use each.
Design-Bid-Build (DBB): The Traditional Method
How it works:
The project is designed first by an engineering firm. Once complete, the design is publicly bid, and the lowest responsive contractor builds the project.
Pros:
- Familiar, well-understood process in the public sector
- Competitive bidding encourages a lower initial construction cost
- Clear separation of roles between designer and contractor
Cons:
- No contractor input during design
- Higher potential for change orders due to constructability issues
- Longer overall schedule (must complete design before bidding)
Best for:
- Straightforward or low-risk projects
- Projects where the lowest construction cost is the priority
Construction Manager at Risk (CMAR): Collaborative and Controlled
How it works:
The owner hires a construction manager (CM) early in the design process. The CM collaborates with the design engineer to provide preconstruction input and later constructs the project under a Guaranteed Maximum Price (GMP).
Pros:
- Early contractor involvement improves cost control and constructability
- GMP offers budget certainty before construction starts
- Accelerated timeline (can overlap design and construction)
- Reduces change orders and disputes
Cons:
- Slightly more complex procurement process
- Requires experienced owner involvement
Best for:
- Complex or fast-tracked projects (e.g., treatment plants, pump stations)
- Projects requiring close coordination during design and construction
- Owners seeking to manage cost risk collaboratively
Design-Build (DB): Fast and Fully Integrated
How it works:
The owner contracts with a single entity (a team with a designer and contractor) to both design and build the project.
Pros:
- Fastest overall delivery method
- One point of responsibility simplifies communication
- Integrated team reduces design-construction conflicts
Cons:
- Less owner control over detailed design
- Changes late in the process can be difficult or costly
- Requires well-developed scope and performance requirements upfront
Best for:
- Projects with clear performance goals and tight deadlines
- Owners are comfortable with a turnkey approach
- Design solutions that are less critical to be customized by the owner
Making the Right Choice
Each method has its strengths — the key is matching the delivery method to the complexity, urgency, budget constraints, and governance requirements of your project.
- Design-Bid-Build works best when predictability and cost competition are top priorities.
- CMAR is ideal when you want early cost certainty and collaboration.
- Design-Build is often the fastest route when the end goal is more important than design specifics.
Need Help Choosing the Right Approach?
Commonwealth Engineers has extensive experience delivering public infrastructure projects under all three methods. Whether you’re planning a water or wastewater treatment facility, a pump station, or a complex utility improvement, we can help you evaluate your project needs and determine the most beneficial solution for your goals, timeline, and budget. Contact Us for more information.