Design-Bid-Build

Design-bid-build (DBB) is the traditional sequential construction delivery method in which the federal government first contracts with an architect/engineer (A/E) firm to complete 100% design documents, then competitively solicits and awards a separate contract to a general contractor to build the designed facility.

What is Design-Bid-Build?

In the design-bid-build sequence, the government procures design and construction through two distinct, sequential contracting actions. First, an A/E firm is selected under Brooks Act procedures (qualifications-based selection rather than price competition) to design the project to completion. Second, once design documents are finalized, the government issues an Invitation for Bid (IFB) to general contractors who compete on price. The lowest responsive, responsible bidder wins the construction contract.

The defining characteristic of DBB is the complete separation of design and construction responsibility. The A/E designs to the government's specifications; the general contractor builds to the A/E's drawings. If design errors cause construction problems, responsibility falls on the A/E (and the government that accepted the design), not the contractor, a point of frequent dispute and litigation in federal construction.

DBB remains the dominant delivery method for routine federal construction because it provides the government maximum control over design quality, enables meaningful price competition among general contractors working from identical plans, and establishes clear liability separation between design and construction. However, it is typically slower than design-build because construction cannot begin until design is fully complete, and change order costs can be high when design deficiencies emerge during construction.

FAR Part 36 and agency-specific supplements govern DBB procurement. For design services, agencies follow the Brooks Act (40 U.S.C. § 1101) qualification-based selection process. For construction, sealed bidding (IFB) is the preferred method per FAR 36.103.

Why Design-Bid-Build matters for government contractors

A/E firms compete for design contracts under qualifications-based selection, past performance, technical approach, and team quality determine selection, not price. General contractors compete purely on price for the construction contract. Understanding which phase a procurement covers determines the competitive strategy.

Example

The GSA Public Buildings Service needs a new federal courthouse. It first selects an A/E firm through Brooks Act procedures to design the $120M facility over 18 months. After approving construction documents, GSA issues an IFB. Eight general contractors submit sealed bids; the lowest responsive bid of $97M is awarded. Construction begins 24 months after the original design contract award.

Frequently Asked Questions

Why does the government use design-bid-build instead of design-build?

DBB provides the government more control over design quality and enables pure price competition for construction. Agencies use it when they have the in-house expertise to manage the A/E relationship, when project requirements are well-defined, and when minimizing construction cost is the priority over schedule.

Can a general contractor also serve as the A/E firm in a DBB project?

Typically no, the A/E and general contractor are separate entities with separate contracts, and organizational conflicts of interest provisions in FAR Part 9 generally prohibit a firm that designed a project from bidding as the construction contractor on that same project.

How are bid bonds used in design-bid-build procurements?

Bidders must submit a bid bond (typically 20% of bid price) with their sealed bid as assurance that they will enter into the contract if selected. If the low bidder withdraws after award, the government can claim the bid bond as liquidated damages for having to re-award to the next lowest bidder.

What are the biggest risks in design-bid-build for contractors?

Differing site conditions (where actual conditions differ materially from what the contract documents indicated), design errors discovered during construction, and scope of work ambiguities are the primary sources of disputes and change order costs in DBB federal construction.