Comparative Project Delivery Methods

Selecting and Managing a Delivery Method

Start with project constraints

A delivery method defines relationships and sequencing. The payment method defines how the constructor is paid. They interact, but design-build is not synonymous with fixed price, and CM as constructor is not synonymous with a GMP on every project. Read the actual agreements before identifying the architect’s client, authority, deliverables, or compensation. Selection requires the owner’s priorities, staffing capacity, funding, procurement rules, design complexity, and acceptable uncertainty.

A project manager should ask when the owner needs reliable pricing, how much design control it wants, whether early trade expertise is valuable, and whether an early construction package can proceed before later design decisions. Then compare the consequences for professional services. An expedited method can increase early staffing and coordination rather than simply reducing the architect’s hours. Do not promise time or cost savings solely from the delivery label.

Design–bid–build

In conventional DBB, the owner contracts separately with the architect and constructor. The architect ordinarily completes a coordinated procurement package before competitive construction bidding. B101, A101, and A201 are commonly used together for conventional projects, subject to their actual scope and modifications. The owner’s design and construction agreements remain distinct.

This sequence allows developed design requirements and comparable bids when the documents and bidder instructions are complete. It often requires design completion before pricing and award, reducing overlap opportunities. Changes or incomplete information can affect bids, construction cost, and schedule. The architect reviews and administers under its agreement; it does not become the constructor or guarantee document perfection. The owner’s obligations concerning furnished design information and the architect’s professional duty must be analyzed separately. A general reference to the Spearin doctrine is not an automatic finding of liability on every public or private project.

For example, an owner prioritizing a fully developed gallery layout and competitive lump-sum bids might prefer DBB. The PM should reserve time for owner decisions, estimates, complete coordination, bidder questions, and award. A lower bid is useful only if it responds to the required work and the bidder can perform it.

Design–build

The owner engages a design-builder for both design and construction under the selected agreement. The architect may contract with the design-builder rather than directly with the owner; an owner may also retain a separate criteria consultant. AIA’s design-build family includes A141–2024 and B141–2024 (which replaces B143–2014). Identify the actual party and service arrangement instead of applying B101 assumptions to every design-build project.

Early design-builder and trade involvement can support concurrent pricing, constructability, and work packaging. The owner must communicate performance criteria and acceptance requirements clearly. Reduced owner involvement in detailed design decisions may be a deliberate tradeoff. The PM must distinguish the design-builder’s pricing authority from the architect’s professional responsibility. A single delivery contract does not eliminate permitting, consultant interfaces, negligence exposure, or the risk of inadequate owner criteria.

For an accelerated clinic, foundation procurement might precede completed interior design. The PM must define the approved structural and equipment loads before releasing foundations, identify unresolved downstream interfaces, and explain the cost of later revisions. Early release is a managed dependency decision rather than a guarantee that unfinished design is safe to build.

Construction manager as adviser

A CMa provides management advice without holding the construction contracts merely by virtue of the adviser role. The owner retains separate construction agreements and needs sufficient capacity to manage those relationships. Typical coordinated AIA forms include C132, B132, A132, and A232. The CMa and architect have distinct estimating, scheduling, review, and administration duties; verify their allocation rather than duplicating or leaving a gap.

CMa can support early planning, estimating, trade packaging, and owner decision-making. An adviser does not automatically guarantee price or construction performance. Multiple owner-held contracts may create interface and coordination risks that the PM must track. Establish who receives applications, reviews schedules, reports exceptions, and communicates approvals before construction begins.

Construction manager as constructor

A CMc participates in preconstruction and later undertakes construction obligations under its agreement. A133 supports cost-plus-fee with a GMP; A134 supports cost-plus-fee without a GMP. A project’s GMP, if used, has stated scope, allowances, contingencies, exclusions, and adjustment provisions. It is not an unconditional guarantee against every owner change or concealed condition.

Early estimates can support design decisions and phased procurement. A GMP negotiated before all details are complete demands clear scope assumptions and a record of what remains unresolved. Distinguish construction contingency from owner reserves and the architect’s fee reserve; they belong to different budgets and cannot be substituted without authority. At a GMP review, verify pricing inclusions, document versions, alternates, and consultant inputs before comparing the proposed price to the owner’s budget.

Convert selection into a work plan

Prepare a responsibility matrix with agreements, package owners, reviewers, issue dates, approval gates, and unresolved interfaces. In DBB, a single coordinated bid issue may dominate the design schedule. In phased design-build or CMc, multiple package releases can require repeated reviews and earlier system decisions. CMa may add an adviser’s review cycle while leaving direct owner contracts intact.

Consider an owner asking for early foundations while a specialist equipment vendor remains unselected. Record the assumed vendor loads and approval authority, compare delay against redesign exposure, and recommend a documented decision. If information is insufficient, the right response may be to defer the affected package. Schedule pressure does not remove the duty to produce coordinated professional work.

Reference: AIA document families and available forms.

Relationship comparison