The Design-Build Schedule: How Much Faster Is It Really, and Where Does the Time Come From?
Updated: Sep 20
Design-build is sold on speed. Owners hear that it is faster, ask how much faster, and get an answer somewhere between a shrug and a sales pitch. The useful question is narrower: where exactly does the time come from, and what has to be true for you to actually get it?
The short version is that a design-build schedule is not faster because anyone works harder. It is faster because activities that normally run one after another are allowed to overlap, and because an entire procurement cycle disappears. Both of those advantages are real, and both can be given back by a slow owner.
What the research actually says
The most cited comparison of North American delivery methods analysed 212 projects completed between 2008 and 2013, by researchers at the University of Colorado Boulder and the University of Florida, and was published in 2018. Measured on total delivery speed from the start of design through completion, design-build came out roughly 102 per cent faster than design-bid-build and about 61 per cent faster than construction management at risk. Measured on construction speed alone, design-build was around 36 per cent faster than design-bid-build and 13 per cent faster than construction management at risk.
The same research found design-build projects experienced less cost growth and less schedule growth than the alternatives, in the range of a few percentage points each. Those numbers are modest, and they are arguably the more important ones, because they describe reliability rather than raw speed.
Treat the headline figures as a direction of travel, not a promise. They are averages across a wide range of project types, and your building is not an average.
Where the design-build schedule saving actually comes from
Overlap: construction starts before design finishes
This is the largest single source of time. Under a traditional model, the design must be complete before it can be tendered and built. Under design-build, site work, excavation, foundations and long-lead procurement can begin while interiors are still being detailed. Nothing was compressed. Two sequential bars on the schedule became one overlapping block.
One procurement instead of two
Selecting a consultant, then completing the design, then preparing tender documents, then tendering, then evaluating, then awarding, is a process that routinely consumes two to four months of calendar time on a commercial project. Design-build runs that process once instead of twice.
No tender-and-award gap
Even a smooth tender has dead time: the period documents sit with bidders, the addenda cycle, the evaluation, the approvals and the contract execution. In design-build that gap is replaced by a team that is already mobilised and already working.
Fewer RFIs, and faster answers to the ones that arise
When the designer and the builder are the same commercial entity, a field question is resolved internally rather than passing through two firms and a consultant review period. The volume of questions does not necessarily drop, but the time each one sits waiting usually does.
Constructability and long-lead buying happen earlier
The builder is in the room while the design is being made, so the choices that cause long lead times, difficult sequencing or scarce trades get flagged while they are still cheap to change. Switchgear, elevators, curtain wall and custom equipment can be released for fabrication earlier.
What you give up in exchange for the time
Speed is bought with early commitment. To let construction start before design is finished, you must lock the things that construction depends on: footprint, structure, envelope, core services capacity and the performance requirements for the systems. If those are still moving, overlap is not acceleration, it is rework.
You also give up some design control and some price transparency compared with a fully tendered set of drawings. That is a real trade, and for some owners it is the wrong one. Design-build is a delivery method, not a moral position.
When design-build is not faster
When the owner cannot decide. The model front-loads decisions. A slow approval chain removes the entire advantage.
When the requirements are genuinely unknown. If nobody can say what the building must do, no delivery method can start it early.
When the approvals authority sets the pace. Site plan approval, permits and utility connections run on their own clock. Overlap does not speed up a municipality.
When the scope is small and simple. On a straightforward fit-out, the procurement saving is modest and the difference between methods narrows.
How to protect the schedule you were promised
Write the schedule into the contract with named milestones, not a single completion date.
Set your own response times and treat them as obligations. Forty-eight hours on routine submittals, shorter on anything that stops work.
Name one decision-maker with real authority and a dollar threshold.
Freeze the structural and envelope package with a signed decision date, and price changes to it honestly.
Track long-lead items separately from the main schedule and review them fortnightly.
Start permitting conversations before you need to. The approvals path is the most common reason a fast schedule becomes an ordinary one.
The honest summary
Design-build genuinely compresses delivery, and the research supports that. But the time comes from overlap and from removing a procurement cycle, and both of those depend on decisions you make rather than effort the builder supplies. The owners who get the fast schedule are the ones who commit early, answer quickly and hold the requirements steady. The owners who do not, get a traditional schedule with a design-build contract wrapped around it.
Common questions about the design-build schedule
How much faster is design-build?
The most cited North American comparison, covering 212 projects completed between 2008 and 2013, found design-build delivered faster than the alternatives with less cost growth and less schedule growth. Treat the headline figures as a direction of travel rather than a promise, because they are averages across a wide range of project types.
Where does the time actually come from?
Overlap, not effort. Construction starts before design is finished, the whole tender cycle disappears, field questions get resolved inside one entity rather than passed between two, and the builder is in the room when the choices that create long lead times are made.
What do I give up for the speed?
Early commitment. To let construction start before the design is finished, you have to lock the things that are expensive to change. You also give up some design control and some price transparency compared with a fully tendered set of drawings.
When is design-build not faster?
When you cannot decide quickly, because the model front-loads decisions and a slow approval chain removes the advantage entirely. When nobody can yet say what the building must do. When the approvals authority sets the pace. And on small, simple scopes, where the procurement saving is modest.
If you are weighing delivery methods for a specific project, the sensible starting point is the decision-making capacity on your own side. You can see how I work with owners and project partners on project solutions.
This article is general information about commercial construction practice in Canada, not legal advice. Have your own counsel review your contract.
Connect with Carolee on LinkedIn: linkedin.com/in/carolee-w-turner-2002417
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