Why Delivery Method Selection Matters

The method used to design and build an infrastructure project isn't just a procurement technicality — it fundamentally shapes the relationships between the owner, designer, and contractor, and determines how risk is allocated across the project. Choosing the right delivery method for a given project can mean the difference between an on-time, on-budget delivery and a contentious, claim-filled experience.

Three methods dominate public infrastructure in the U.S. today: Design-Bid-Build (DBB), Design-Build (DB), and Construction Manager at Risk (CMAR). Each has strengths and limitations.

Design-Bid-Build (DBB): The Traditional Approach

DBB is the most familiar and historically dominant delivery method for public infrastructure. The sequence is sequential: the owner hires a designer to produce complete construction documents, then competitively bids the work to contractors.

Strengths

  • Strong price competition among bidders
  • Clear separation of design and construction responsibility
  • Well-established legal and regulatory framework
  • Owner retains maximum design control

Limitations

  • Longer overall schedule (design must be complete before construction procurement begins)
  • Contractor has no input during design, limiting constructability feedback
  • Change order disputes common when field conditions differ from design assumptions
  • Innovation in construction methods is limited

Best for: Routine, well-defined projects with minimal complexity, stable scopes, and sufficient time for sequential delivery.

Design-Build (DB): Speed and Integration

In Design-Build, a single entity — typically a joint venture or a contractor with an in-house or contracted design team — is responsible for both design and construction. The owner contracts with one party for the entire delivery.

Strengths

  • Compressed schedule through overlapping design and construction phases
  • Single point of accountability for owner
  • Contractor input drives constructability and value engineering
  • Cost certainty established earlier in the process

Limitations

  • Owner must define requirements (performance specs) rather than prescriptive plans — requires sophisticated owner capacity
  • Less owner control over design details
  • Independent quality oversight requires deliberate effort
  • Not all state/local procurement laws readily accommodate DB

Best for: Large, complex, or time-sensitive projects; projects where scope is defined by performance outcomes rather than prescriptive design; emergency reconstruction.

Construction Manager at Risk (CMAR): Collaboration with Cost Certainty

CMAR brings a contractor on board early — during design — in an advisory role, then transitions to a Guaranteed Maximum Price (GMP) contract for construction. The owner maintains separate contracts with designer and CM.

Strengths

  • Early contractor involvement improves constructability and reduces design errors
  • Owner retains design control while benefiting from contractor expertise
  • GMP provides cost protection without sacrificing design quality
  • Strong collaborative environment reduces adversarial dynamics

Limitations

  • More complex procurement and contract structure
  • GMP is only as reliable as the design completeness at the time it's established
  • May require enabling legislation in some jurisdictions

Best for: Complex projects where the owner wants design involvement and contractor collaboration; phased projects; projects where innovation in construction methods adds value.

Quick Comparison

Factor Design-Bid-Build Design-Build CMAR
Schedule Longest Fastest Moderate
Owner Control High Low–Moderate High
Cost Certainty At bid Early At GMP
Risk Transfer Moderate High to contractor Shared
Complexity Fit Low–Medium High Medium–High

Making the Right Choice

The best delivery method depends on project-specific factors: scope certainty, schedule urgency, owner capacity, available procurement authority, and risk tolerance. Engaging an experienced construction manager or owner's representative early in project development helps match delivery strategy to project reality — before procurement decisions lock in the approach.