AIA Contract Series · ARE 5.0 Exam Prep · Updated May 2026
AIA B143 explained for ARE 5.0
A plain-language breakdown of the Design-Builder-Architect Agreement — what it covers, how the architect fits into a design-build team, and why it matters for your exam.
What is AIA B143?
The AIA B143 — formally titled Standard Form of Agreement Between Design-Builder and Architect — is the contract that governs the relationship between the design-builder and the architect when the architect is hired as a subconsultant on a design-build project. The 2014 edition is the version tested on the ARE 5.0.
In a design-build project, the owner contracts with a single design-builder under A141. If the design-builder is a contractor who does not have in-house design capabilities, they hire an architect to provide design services. B143 is the contract between the design-builder and that architect. B143 functions similarly to C401 in design-build delivery because the architect works under another project entity rather than directly for the owner — but B143 remains an architect agreement with its own professional obligations, not a simple consultant arrangement.
Why B143 appears on PjM and PcM
B143 is tested on Project Management and Practice Management because it fundamentally changes the architect’s professional role, liability exposure, and business relationships compared to traditional delivery.
PjM
Project Management
Covers how the architect manages design services within a design-build team, coordinates with the contractor-led design-builder, and delivers design documents that serve both design and construction purposes simultaneously.
PcM
Practice Management
Covers the business and professional implications of working as a subconsultant to a contractor, how liability shifts in design-build, how firms structure their involvement in design-build teams, and the ethical considerations of the architect’s changed role.
The architect’s changed role under B143
Understanding how B143 changes the architect’s role compared to traditional delivery is one of the most important concepts tested on PjM and PcM:
Architect works for the design-builder
Not the owner
Under B143, the architect’s client is the design-builder — typically a general contractor. The architect has no direct contract with the owner. This is a fundamental shift from traditional delivery where the architect contracts directly with the owner under B101.
Exclusive benefit of the design-builder
Services are not for the owner’s benefit
Under B143 §2.4, the architect’s services are performed in the sole interest and for the exclusive benefit of the design-builder — not the owner. This reinforces that the architect is not acting as an independent advisor to the owner in design-build delivery, and cannot be expected to advocate for the owner’s interests independently.
No independent advocate role
Architect cannot be impartial
In traditional delivery, the architect serves as an impartial administrator between the owner and contractor. Under B143, the architect works for the design-builder and cannot serve as an independent advocate for the owner. If there is a dispute between the owner and design-builder, the architect’s employer is one of the parties — not an impartial administrator.
Coordination with A141 obligations
Design-builder’s contract governs
B143 coordinates with and supports the design-builder’s obligations under A141. The architect must perform services consistent with what the design-builder owes the owner — the architect’s work is shaped by A141’s requirements flowing through the design-builder.
Scope of services
Shaped by the design-builder and Owner’s Criteria
The architect’s services are shaped by the design-builder’s obligations and the Owner’s Criteria established in A141. Unlike B101 where the architect defines their own services in negotiation with the owner, under B143 the scope is defined by what the design-builder needs to fulfill their prime contract.
Instruments of service
Both parties retain ownership
Both the design-builder and architect retain ownership of their respective Instruments of Service while granting limited project-use licenses. This is more complex than traditional delivery — the architect retains copyright over their design work, but both parties hold ownership interests relevant to their respective contributions.
Compensation
Paid by the design-builder
The architect is compensated by the design-builder under B143 — not by the owner. The design-builder receives payment from the owner under A141 and pays the architect from those funds. This creates a dependency on the design-builder’s financial health and payment practices.
B143 compared to B101 and C401
B101
Traditional delivery — architect contracts with owner
The architect’s client is the owner. The architect is an independent professional who serves as an impartial administrator during construction. The architect defines their own scope and is paid directly by the owner.
C401
Traditional delivery — architect hires consultants
The architect contracts with subconsultants to assist with the project. The architect is the prime professional and the consultant works under the architect’s direction. The architect pays the consultant from funds received from the owner.
B143
Design-build — architect works for design-builder
The architect’s client is the design-builder — typically a contractor. The architect has no direct relationship with the owner. The architect’s services are performed for the exclusive benefit of the design-builder. The architect’s scope is shaped by the design-builder’s obligations and the Owner’s Criteria. The architect is paid by the design-builder and cannot act as an impartial administrator.
Common exam traps
- Under B143, the architect’s client is the design-builder — not the owner.
- The architect’s services are performed for the exclusive benefit of the design-builder, not the owner.
- The architect cannot act as an impartial administrator between the owner and design-builder under B143.
- B143 coordinates with the design-builder’s obligations under A141 — the architect’s work supports those obligations.
- The architect is paid by the design-builder — not directly by the owner.
- B143 functions similarly to C401 in design-build delivery, but remains an architect agreement — not a simple consultant arrangement.
- The architect’s scope is shaped by the design-builder’s obligations and the Owner’s Criteria — not negotiated directly with the owner.
- Both the design-builder and architect retain ownership of their respective Instruments of Service.
Exam tip
When an ARE question describes a design-build project where the architect is working for a general contractor rather than the owner — that relationship is governed by B143. The most important things to remember: the architect’s services are performed for the exclusive benefit of the design-builder, not the owner; the architect cannot be an independent advocate for the owner; and their scope and compensation both flow through the design-builder. Everything about their professional role is filtered through that relationship.
How B143 relates to other AIA contracts
B143 sits within the design-build contract family alongside A141 (Owner-Design Builder Agreement). A141 governs the owner-design builder relationship, and B143 governs the design-builder-architect relationship — coordinating with A141’s obligations the same way C401 coordinates with B101 in traditional delivery. Understanding the parallel structure between traditional delivery (B101 → C401) and design-build delivery (A141 → B143) is one of the most effective ways to organize your knowledge of AIA contracts for the ARE.