Design-Bid-Build: Traditional Sequential Delivery

How the Design-Bid-Build delivery method sequences design completion before competitive bidding and construction, the contractual relationships it creates, its advantages and disadvantages for owners and architects, and how the AIA A201 Conventional family supports this approach.

ARE · Practice Management

Overview

Design-Bid-Build is the oldest and most common delivery method in the United States. The name tells you the sequence: complete the design first, put it out for competitive bids second, then build. Three distinct phases. Three distinct roles. Two separate contracts, one between owner and architect, the other between owner and contractor.

The method is built on a simple premise. Finish the design before selecting a contractor, so the owner knows exactly what the project costs before construction starts. That price certainty is the reason public agencies have used DBB for more than a century. Sealed competitive bids, lowest-responsive-and-responsible bidder wins. Taxpayer money protected by open competition.

But that sequential structure carries trade-offs. The contractor has zero input during design. That means constructability problems stay hidden until bids come in or construction begins. And the timeline is longer than overlapping methods like Design-Build or CM-at-Risk, because each phase must finish before the next can start.

The AIA Conventional (A201) family of contract documents was built around DBB. A101 for the owner-contractor agreement, B101 for the owner-architect agreement, and A201 as the keystone general conditions document connecting them. When you see "Conventional family" on the exam, think DBB.

For the ARE, you need to know when DBB works best, where it creates risk, and how it compares to alternative delivery methods.

Essential

Design-Bid-Build follows a strict linear sequence. The architect completes the design. The owner solicits competitive bids based on those completed documents. A contractor is selected. Then construction begins. Each phase starts only after the previous one finishes. This three-phase structure produces three distinct roles and two separate contractual relationships. ## The Three Phases Design Phase. The owner contracts with an architect (through B101 or a similar agreement) to develop the full design. This progresses through the standard five phases: schematic design, design development, construction documents, and then the documents are packaged for bidding. During design development, the drawings fix the size and character of the project and expand upon schematic design work. By the end of construction documents, the drawings and specifications are detailed enough for a contractor to price and build from. A critical feature of DBB: the contractor is not involved during design.

Professional

Consider a county government commissioning a new 40,000 SF public library. State procurement law mandates competitive bidding. The county hires an architect through a qualifications-based selection process, and the architect develops the full design over 14 months. Once construction documents are complete, the county advertises for sealed bids. Six general contractors submit lump-sum proposals. The lowest responsive and responsible bidder wins the contract. This is textbook DBB. The county got exactly what the procurement statute demands: open competition, price certainty, and a clear paper trail for accountability. The architect had full creative control during design. The taxpayers can see that the lowest qualified bidder won the work. But four months into construction, the contractor discovers that the structural drawings conflict with the MEP routing in the ceiling plenum. The architect's drawings show ductwork running through a zone occupied by steel beams.

TLDR

DBB = complete design first, then competitive bid, then build. Three phases, strictly sequential.
Two contracts: owner-architect (B101) and owner-contractor (A101). No contract between architect and contractor.
The AIA Conventional (A201) family was built for DBB. A201 is the keystone document.
Biggest advantage: price certainty. The owner knows the cost before construction starts.
Biggest disadvantage: no contractor input during design. Constructability problems stay hidden until it is too late.
Spearin Doctrine means the owner implicitly warrants the design documents. Design errors = owner exposure.
Public agencies use DBB because procurement statutes require competitive sealed bidding.
Adding a CM during design phase fills the constructability gap without changing the delivery method.
Lowest bid does not equal lowest project cost. Change orders from design issues can erase the savings.
On the ARE, the contractor's only contract in DBB is with the owner. Period.

ELI5

Think about ordering a custom birthday cake from a bakery. First, you sit down with the cake designer and plan every detail. Chocolate layers, raspberry filling, buttercream frosting, a specific decoration on top. You approve the design before anyone starts baking. That is the Design phase. Next, you show the design to three different bakers and ask each one to tell you their price. You pick the baker who gives you the best deal. That is the Bid phase. Finally, the baker you picked makes the cake exactly as designed. That is the Build phase. Here is the key thing to notice: the baker was not involved when you planned the cake. The baker did not get to say, "Hey, that decoration would be really hard to make. If you changed it slightly, it would look just as good and cost less.

AREPractice Management

Design-Bid-Build: Traditional Sequential Delivery

2 min read220 words

Why Design-Bid-Build Still Dominates American Construction

For the ARE, you need to know when DBB works best, where it creates risk, and how it compares to alternative delivery methods.

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