7.2 Public Works, Construction Delivery & Qualifications-Based Selection
Key Takeaways
Design-bid-build separates design and construction contracts, while design-build integrates their responsibility.
CMAR introduces construction expertise during design and uses the negotiated guaranteed-maximum-price structure defined by the agreement.
Job order contracting uses scoped orders and agreed unit-price-book coefficients within the authorized master agreement.
Note
Numerical thresholds, notice periods, approval routes, and local procedures in the examples are hypothetical agency rules unless a specific applicable federal rule is identified. Verify the governing jurisdiction, award terms, solicitation, and contract before treating a procedure as mandatory.
Foundations of Public Works and Capital Construction
Procuring capital construction and public works infrastructure is fundamentally distinct from acquiring standard commercial goods and services. Construction projects are fixed to real property, highly capital-intensive, subject to unpredictable physical site conditions, and governed by specialized statutory requirements, including statutory surety bonding, prevailing wage mandates, and licensing laws.
In public construction, the baseline legal relationship between the public owner, design professional, and general contractor is defined by the Spearin Doctrine (United States v. Spearin, 1918). Under this landmark legal principle, when a public owner provides detailed design plans and specifications to a construction contractor, the owner impliedly warrants that those plans are accurate, complete, and buildable. If the specifications contain defects or omissions, the public entity—not the contractor—is legally and financially responsible for resulting delays, redesign expenses, and construction change orders.
Construction Project Delivery Methods
A project delivery method defines the contractual relationships, roles, and operational sequence connecting the public owner, the design team (architects and engineers), and the construction team (builders and trade contractors).
Traditional Design-Bid-Build (Linear, Separate Contracts):
[ Public Owner ] ─────── Contract 1 ───────> [ Architect/Engineer (A&E) ]
│ (Produces 100% Plans/Specs)
└──────────────── Contract 2 ───────> [ General Contractor (Lowest Bidder) ]
Alternative Design-Build (Integrated Single Contract):
[ Public Owner ] ─────── Single Contract ──> [ Design-Build Entity ]
├── In-house or Subcontracted A&E
└── Construction Trade Teams
Construction Manager at Risk (CMAR):
[ Public Owner ] ─────── Contract 1 ───────> [ Architect/Engineer (A&E) ]
│
└──────────────── Contract 2 ───────> [ Construction Manager (CMAR) ]
├── Preconstruction Constructability
└── Guaranteed Maximum Price (GMP)
1. Design-Bid-Build (DBB) — The Traditional Linear Method
Design-Bid-Build remains the historical standard for public infrastructure projects.
- Three Sequential Phases:
- Design: The owner contracts independently with an Architectural & Engineering (A&E) firm to prepare 100% complete construction drawings and technical specifications.
- Bid: The agency issues an Invitation for Bids (IFB) advertising the completed plans. General contractors submit competitive sealed lump-sum bids.
- Build: The agency awards the construction contract strictly to the lowest responsive and responsible bidder. The A&E firm typically provides construction administration services to inspect work on the owner's behalf.
- Advantages: Maximizes open price competition; transparent public bid opening; straightforward award criteria; owner retains absolute control over design details.
- Disadvantages: Longest project duration because phases cannot overlap; adversarial relationships between architect and contractor; owner can bear design-specification risk under applicable law; highly susceptible to low-ball bidding where contractors bid below cost and seek to recover profits through aggressive change orders.
2. Design-Build (DB) — Single Point of Responsibility
Under Design-Build, the public owner executes a single contract with a single legal entity (the design-builder) responsible for both complete architectural/engineering design and physical construction.
- Fast-Tracking (Schedule Compression): Design and construction phases overlap. Construction site preparation, excavation, and foundation work proceed while final interior architectural and mechanical drawings are still being completed, significantly reducing overall project delivery time.
- Risk Transfer: Shifts the risk of design errors and omissions from the public owner to the design-build contractor. The design-builder generally bears its own design-coordination risk, but owner-directed changes, defective owner criteria, and other contractually allocated risks can still support adjustments.
- Disadvantages: The public owner loses the independent designer who serves as the owner's advocate during construction inspection; requires highly sophisticated initial "bridging documents" or performance specifications; requires early owner commitments to design concepts before detailed drawings are produced.
3. Construction Manager at Risk (CMAR / CM-GC)
In Construction Manager at Risk (also called Construction Manager/General Contractor or CM-GC), the public owner retains an independent A&E firm for design, but contracts with a construction manager early in the preconstruction planning phase.
- Preconstruction Services: During design, the CMAR provides value engineering, constructability reviews, accurate cost estimating, and project scheduling assistance to the owner and architect.
- Guaranteed Maximum Price (GMP): At a defined design milestone (typically 60% to 90% completion), the CMAR negotiates a binding Guaranteed Maximum Price (GMP) with the owner. The CMAR assumes the financial risk of completing the project within the GMP, acting as the general contractor.
- Open-Book Bidding: The CMAR competitively solicits trade subcontracts using open-book bidding, allowing the public owner complete transparency into subcontractor costs and contingency allowances.
4. Job Order Contracting (JOC)
Job Order Contracting is an Indefinite Delivery/Indefinite Quantity (IDIQ) delivery method specifically designed for recurring maintenance, repair, alteration, and minor construction projects.
- Unit Price Book (UPB): The public agency adopts an objective, standardized Unit Price Book (such as RSMeans) containing thousands of pre-priced construction line-item tasks with established labor, material, and equipment unit prices for the local geographic market.
- Competitive Coefficient: Contractors bid competitive adjustment factors (called coefficients or multipliers) applied against the published UPB line items (e.g., 0.95 for standard business hours, 1.05 for non-standard hours).
- Rapid Task Order Issuance: Once the master JOC agreement is awarded, individual facilities maintenance or renovation projects are scoped via rapid on-site reviews. The agency multiplies the agreed UPB task prices by the contractor's coefficient to calculate the fixed project task order price, cutting procurement lead times from months to days.
A regional municipal transit authority needs to replace an aging bridge structure carrying light rail tracks over an interstate highway. The project has an aggressive nine-month completion deadline before a major regional athletic event. The authority requires design and construction to proceed concurrently to compress the schedule, and wants a single entity to assume full contractual responsibility for design coordination, permitting, and physical construction. Which project delivery method best achieves these goals?
Job Order Contracting (JOC), because unit price books are statutorily required for all municipal rail transit repairs.
Traditional Design-Bid-Build (DBB), because sequential 100% design drafting followed by formal sealed bidding provides the fastest schedule velocity.
Design-Build (DB), because contracting with a single integrated design-build entity allows fast-tracking where construction begins before design completion, while transferring design error risk away from the owner.
Construction Manager as Advisor (CMA), because multi-prime contracting eliminates contractor change orders.
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