What a project delivery method is

Before a single drawing is finished, an owner who wants a building, a bridge or a treatment plant has to answer a question that shapes everything that follows: who will design it, who will build it, how they will be chosen, how they will be paid, and how the risks of getting it wrong will be shared. The answer is the project's delivery method. Two hospitals of the same size, with the same budget and the same site, can turn out very differently because one was delivered by design-bid-build and the other by a public-private partnership. The method decides when the builder joins the team, how much the owner controls the design, how soon the price is known, how fast the work can start, and what happens when something goes wrong.

This course looks at the main delivery methods used in North American construction, from the owner's side and from the contractor's side. CON-100 lesson 7 gave a one-page overview. Here we go deeper: how each method is organized and procured, how the contractor is paid, how cost and schedule behave, which standard contracts are used, where the method works well and where it fails, and how owners choose. Contract law and standard forms in general are in CON-220, tendering law in CON-220 lesson 3 and CON-300 lesson 10, buying subcontracts and supply in CON-330, and the detailed allocation of risk, insurance and bonding in CON-350.

Four separate decisions

People often use "delivery method" loosely to mean several different things. It helps to separate four decisions that an owner makes, because they can be combined in many ways.

So "design-build" does not by itself tell you whether the design-builder was chosen on price or on qualifications, or whether it is paid a lump sum or its costs plus a fee. A public owner might procure a design-build contract by a two-stage best-value process and pay a stipulated price; a private developer might negotiate a design-build contract with one trusted firm on a cost-plus basis with a guaranteed maximum price. Both are design-build. Keeping the four decisions apart avoids a lot of confusion in meetings, contracts and claims.

The main delivery methods

Most projects in Canada and the United States are delivered by one of six families of methods. The lessons that follow take them one at a time.

Each method is a different way of drawing the lines of contract between the owner, the designer and the builder. The simplest way to see the differences is to draw the contracts. In design-bid-build the owner holds two contracts, and the designer and builder have no contract with each other. In design-build the owner holds one. In integrated project delivery the owner, designer and builder sign the same agreement. In a P3 the owner signs with a special-purpose company that itself holds the design, construction and maintenance contracts and borrows money to pay for the work.

What changes from method to method

Delivery methods differ along a handful of dimensions that matter to every owner. Most choices are trade-offs between them.

No method wins on every dimension. The owner who wants to control every detail of the design will struggle to also give one party full responsibility for the result. The owner who wants the earliest possible start must accept that the price will be fixed before the design is finished, or not fixed at all until later. The art of choosing a delivery method, which lesson 11 treats in detail, is to know which dimensions matter most for this project and this owner.

A short history

For most of the twentieth century, public construction in North America was overwhelmingly design-bid-build. The method grew out of public procurement rules that required open, competitive, low-price bidding to prevent patronage, and it fitted a world in which the architect or engineer was the owner's trusted professional and the contractor simply built what was drawn. Construction management emerged in the 1960s and 1970s as projects grew more complex and owners wanted construction expertise during design and the ability to start work before design was finished. Design-build, the oldest method of all if you count the master builders of history, revived strongly from the 1990s, first in private industrial work and then in public highways and buildings. Integrated project delivery appeared in the 2000s, inspired by lean construction and by alliancing in Australia and the United Kingdom. Public-private partnerships for social infrastructure took off in Canada from the early 2000s, led by Partnerships British Columbia and Infrastructure Ontario, and more slowly in the United States, mainly for toll roads, managed lanes and some transit and social infrastructure.

In Canada today, public owners use a wide mix. Infrastructure Ontario's June 2026 market update, for example, lists projects in design-bid-build, design-build, design-build-finance, design-build-finance-maintain, construction management at risk and alliance models, and its transit pipeline includes the Yonge North Subway Extension under an alliance. Municipalities still deliver most of their work by design-bid-build, while large hospitals and transit lines use partnership, alliance or progressive models.

How the method changes the contractor's job

For a construction manager or contractor, the delivery method changes the job far more than the size or type of the project. In design-bid-build the contractor's job begins with a complete set of documents, a short bid period and a price that must be right the first time; the skills that win are estimating accuracy, subcontractor relationships and tight cost control. In construction management the contractor is hired for its judgment during design: estimating at each design stage, constructability review, scheduling, and buying trade packages in sequence. In design-build the contractor leads or partners with a design team and carries the design risk, so it needs design management skills and a strong relationship with its designers. In IPD the contractor shares profit and loss with the owner and designer and must work in an open-book, collaborative way. In a P3 the contractor is one member of a consortium with financiers and a facility manager, under a contract that may run thirty years.

A first look at cost and time

Delivery methods affect total project time mostly through overlap. In design-bid-build, design, bidding and construction happen one after the other. Methods that bring the builder in early allow the contractor to buy and start some work, such as site preparation, foundations or long-lead equipment, while the rest of the design is still being finished. That is called fast-tracking. The simple model below compares the three classic sequences for an invented project with twelve months of design and twenty months of construction.

# Simple timeline model (months) for one project under three delivery methods (illustrative)
design, construct = 12, 20
bid_dbb = 3                      # advertise, bid, evaluate, award after design is complete
procure_cm = 2                   # select the construction manager early, during design
procure_db = 4                   # two-stage design-build selection before design starts

dbb = design + bid_dbb + construct
# CMAR: construction starts at 60 % design (packages bid in sequence); 2 months of overlap lost to sequencing
cmar = procure_cm + 0.6 * design + construct + 2
# DB: design-builder starts site work at 40 % design; design time shortened 15 % by working with the builder
db = procure_db + 0.4 * design * 0.85 + construct + 1
for name, t in [("Design-bid-build", dbb), ("CM at risk", cmar), ("Design-build", db)]:
    print(f"{name:17} {t:5.1f} months   saving vs DBB {dbb - t:4.1f}")

Design-bid-build   35.0 months   saving vs DBB  0.0
CM at risk         31.2 months   saving vs DBB  3.8
Design-build       29.1 months   saving vs DBB  5.9

In this illustrative model, construction management at risk and design-build save several months compared with design-bid-build. Real savings depend on the project. Studies comparing methods, such as the Construction Industry Institute and Penn State research in the late 1990s and later research by the Design-Build Institute of America and university groups, generally found design-build and CMAR projects faster on average than design-bid-build, but the samples, definitions and project types vary, and a badly run fast-track can lose all of its theoretical advantage in redesign and changes. Lesson 4 models overlap in more detail.

Who takes which risks

Every method allocates risks differently. The headline risks are the same on every project: the design may be incomplete or wrong, quantities may differ, ground conditions may be worse than expected, prices may rise, permits may be late, the owner may change its mind, and the building may not perform. In design-bid-build, the owner carries design risk because it hired the designer and warranted the drawings to the contractor; the contractor carries price risk on what is shown. In design-build, the design-builder carries most design risk and price risk once the price is fixed. In IPD, the parties share most risks through a common profit pool. In a P3, the private partner carries design, construction, financing and long-term performance risk, and the owner pays only when the asset is available to use. CON-350 explores risk allocation in depth; lesson 11 of this course uses a simple risk matrix to compare methods.

The owner's capacity

A method is only as good as the owner using it. Design-bid-build demands that the owner, through its designer, produce complete and coordinated documents. Agency construction management demands that the owner manage many trade contracts. Design-build demands that the owner write a clear performance-based statement of requirements and then resist the urge to redesign the project during review. IPD demands that the owner's staff sit in the big room and make decisions quickly. P3s demand sophisticated legal, financial and technical advisers and long-term contract management. Owners who choose a method they cannot staff often blame the method for failures that were really failures of capacity.

# Rough owner staffing estimate by delivery method for a $120 million project (illustrative full-time equivalents)
fte = {   # (design phase, construction phase)
    "Design-bid-build":          (2.0, 3.0),
    "Agency CM (multiple prime)": (2.5, 4.5),
    "CM at risk":                (2.5, 3.0),
    "Design-build":              (3.0, 2.5),
    "IPD":                       (3.5, 3.0),
    "P3 (DBFM)":                 (5.0, 2.0),   # heavy advisory load before financial close
}
design_months, build_months = 14, 26
for m, (d, c) in fte.items():
    print(f"{m:27} {d * design_months + c * build_months:6.0f} person-months")

Design-bid-build               106 person-months
Agency CM (multiple prime)     152 person-months
CM at risk                     113 person-months
Design-build                   107 person-months
IPD                            127 person-months
P3 (DBFM)                      122 person-months

The numbers are illustrative, but the pattern is real: methods differ less in total owner effort than in when that effort is needed and what skills it requires. P3s concentrate effort early, in preparing output specifications, risk analysis and procurement; agency CM concentrates it during construction, in managing many trade contracts.