Design build vs design bid build: the difference between the two methods
The main difference between design build and design bid build is whether design and construction are joined under one team or split between two.
In design build, one team handles both the design and the construction under a single contract whereas in design bid build or design-bid-build, the owner hires a designer first, and once the design is complete, hires a separate builder later, after the work has been put out to bid. To bid the work means builders send in their prices to win the job.
Both are common ways to deliver on a construction project. This article explains each method, how they differ, the types of design build, and when each method is applicable.
What is design build?
Design build is a delivery method where one team designs the project and builds it under a single contract. The owner signs one agreement with one party, often called the design builder. That team can be a builder with designers on staff, a designer paired with a builder, or a joint venture, which means two firms teaming up as one. The Design-Build Institute of America describes design build as one entity, one contract, and one flow of work from start to finish.
The designers and the builders sit on the same team, so they can plan together from the very start. The people who will build the project can give input on cost and on how easy the design is to build while it is still taking shape. This tends to reduce surprises later on. The owner still reviews and approves the design, but only has to deal with one point of contact instead of two.
This type of method is best for projects with tight timelines and clear, well-defined scopes where the owner wants to transfer risk and lock in a guaranteed maximum price early.
What is design bid build?
Design bid build is the traditional delivery method, where design and construction happen in three separate steps, one after another. First, the owner hires a designer, usually an architect or an engineer, to create the full design. Second, the finished design goes out to bid, so builders can send in their prices. Third, the owner hires the chosen builder, often the one with the lowest price, to construct the project.
The owner holds two separate contracts here, one with the designer and one with the builder. The AIA Contract Documents are a widely used set of standard agreements that set out these roles. The designer and the builder do not work together during the design stage. The builder joins only after the design is done, so the design is complete before anyone prices or builds it. One point owners often value here is more direct control over the design, since they work with the designer on their own before any builder is involved.
This type of method is good for standard projects with strict procurement rules (like public schools or roads) where the owner wants complete control over the design before hiring a builder.
Design build vs design bid build: the main differences
Choosing either of the methods can influence the way the project is carried out. The differences are mostly seen in the contracts, the schedule, the cost, the risk, and how the team is chosen.
In design build, one team carries out both jobs, so the two move together and one party is accountable for how they fit. Cost and buildability are considered while the design is still forming.
In design bid build, the design is finished first and handed to the hired builder, so the two never overlap. The owner gets a clear, fixed design, but also manages the link between the two sides.
Below are some of the common differences between design build and design bid build are:
Contracts
In design build, the owner signs one contract with a single team. In this method, there is one point of contact and one party is responsible for the whole project.
In design bid build, the owner signs two contracts, one with the designer and one with the builder. Here, two separate contracts mean the owner is the point of contact between the designer and the builder.
Costs
In design build, the price is shaped as the design develops, so cost is weighed at every stage instead of only at the end. Since the team includes the designer and the builder, it can run value engineering early, which means finding cheaper ways to deliver the same function before the design is locked in. Value engineering is a method of finding cheaper ways to deliver the same function while the design can still change.
Design bid build sets the full price after the design has been completed and the bids come in. Every builder bids on the same finished drawings, so the owner can compare prices side by side, and open competition can push the starting price down. The lowest bid is not always the final cost, though, since work that was not clear in the drawings can add to the price once construction begins.
Timing
Design build lets design and construction overlap, so construction can start early, even while the design is still being finished. This overlap is called fast-track, and it can shorten the time taken to complete the project, though the effect depends on the project.
Design bid build runs in strict order, and building begins only after the design has been completed and bidding is done.
Risk
Design build places one team in charge of both design and construction, so gaps between the two are that team's problem to fix. Design bid build leaves more of that gap with the owner. If the design and the build do not match, the designer and builder may blame each other, and the owner can be caught in between. That kind of mismatch often leads to a change order, which is a formal change to the contract that adds cost or time.
Choosing the team
Design build often picks the team based on a mix of skill, experience, and price, not on price alone.
Design bid build usually picks the builder mainly on price, through competitive bidding, where builders compete to offer the lowest cost. The way the team is chosen can shape how the rest of the project runs. For example, a team picked for teamwork behaves differently from one picked only for a low number.
Other types of design build
Some of the other types of design build are:
Progressive design build
Progressive design build selects the team early, mainly on qualifications, which is sometimes called qualifications-based selection. The owner and team then work through the design and the price together, in two phases: a preconstruction phase to develop the design, then a construction phase once the price is agreed. The price is usually set as a guaranteed maximum price later in the design.
Progressive design build is good for complex, highly specialized, or fast-tracked projects where the owner wants early collaboration with the builder but isn't ready to commit to a fixed price up front.
Best-value design build
In best-value design build, the project owner picks the team based on price, qualifications, and design quality, rather than the price alone. Teams usually submit a price with their proposal, so the owner weighs cost and quality together while choosing.
It usually involves a two-step process. First, the owner narrows down the pool based on qualifications (experience, team chemistry). Second, the remaining teams submit a technical design proposal alongside a price. The owner scores both sections to find the highest total value. This type of design build is best for complex, highly technical, or visually unique projects where innovation and expertise matter more than just cutting corners on cost.
Lump-sum design build
In lump-sum design build, also called fixed-price design build, the project owner gives a strict set of requirements and teams compete based on the lowest total cost. Price carries more weight in the choice, and the owner gets cost certainty sooner, with less room to change the design later. This type of design build is best for standard, straightforward projects where the owner knows exactly what they want and price is the only major factor.
When each method tends to be used
Each method tends to be used based on what the project owner needs and what they are building. Design bid build tends to suit owners who want a clear, fixed design in hand before any building starts, and who want to compare prices side by side. It also tends to suit projects where the design is simple and well understood, so there is little need for the builder to help shape it.
Design build tends to suit owners who want a single point of responsibility and who value speed and early cost input. It is often used on projects with tighter timelines, or on projects with complex parts that gain from close teamwork between designers and builders. Design build has grown into one of the most widely used delivery methods, though design bid build remains common, and both continue to be used across the industry.
Conclusion
Design build and design bid build are two of the most common ways to deliver a construction project, and the core difference comes down to contracts, timing, and risk. Design build puts design and construction under one team and one contract, which lets the work overlap and the price take shape early. Design bid build keeps design and construction separate, finishes the design first, then bids the build, which gives a firm price at a later point and puts more coordination on the owner. Progressive design build offers a middle path that keeps the single team while setting the price in stages. Neither method is better in every case. The right fit tends to depend on what the owner values most, such as speed, cost certainty, control, and how closely they want the designers and builders to work as one.
Frequently asked questions (FAQs)
Does design bid build always pick the lowest bid?
Design bid build does not always pick the lowest bid. Design bid build often selects the work to the lowest qualified bidder, but some owners set rules that also weigh a builder's experience and past work. So price is a major factor, but not the only one in every case.
Can the price change in design build?
Yes, the price in design build can still change if the owner changes the scope of the work. The method sets a price as the design develops, but added or altered work can adjust that figure, just as it can in most delivery methods.
Are design build and design bid build used for the same kinds of projects?
Both methods are used across many project types, from small buildings to large infrastructure. The choice tends to depend on the owner's priorities, such as speed, cost certainty, and how much control they want over the design, rather than on the type of building alone.
Is design build faster than design bid build?
Design build can be faster, since design and construction can overlap instead of running one after another. This is not guaranteed, though. The real timeline depends on the project, the team, and how clear the owner's goals are from the start.
Which method costs less, design build or design bid build?
Neither method is always cheaper. Design bid build uses competitive bidding, which can lower the starting price, but change orders can add to the cost later. Design build gives cost input earlier and fewer gaps between design and build, though the team is not always chosen on price alone. The final cost tends to depend on the project rather than on the method by itself.
What other delivery methods exist besides these two?
Owners also use methods such as construction manager at risk and integrated project delivery. Construction manager at risk brings a builder on early to advise during design, then holds the construction price. Integrated project delivery shares the risk and the reward across the owner, the designer, and the builder under one shared agreement.