EOR vs. DOR: Who Owns the Design?
Design responsibility is often summarized with a single acronym, but EOR and DOR describe distinct roles with different implications depending on project type, delivery method, and jurisdiction. Understanding the difference is essential for aligning expectations, managing risk, and avoiding gaps in responsibility—especially on multidisciplinary projects.
EOR — Engineer of Record
The Engineer of Record (EOR) is the licensed professional responsible for the technical accuracy and code compliance of a defined scope of work. For MEP systems, the EOR establishes design intent, prepares or oversees the engineering documents, and applies their professional seal where required.
In practice, the EOR’s role centers on design authority. This includes defining system performance criteria, coordinating with other disciplines, and responding to questions that affect the integrity of the design. While the EOR may rely on delegated design or manufacturer input, responsibility for overall compliance and intent remains with the EOR for their discipline.
On private-sector projects, “EOR” is the most commonly used term to describe this responsibility, even when multiple engineers of record exist across disciplines.
DOR — Designer of Record
The Designer of Record (DOR) is a term most often used in government and public-sector contracting. Unlike EOR, DOR emphasizes contractual responsibility rather than licensure alone. The DOR is the entity contractually accountable to the Owner for delivering the design scope, which may include work performed by multiple licensed professionals.
In many public projects, the DOR may be a firm rather than an individual, with licensed engineers serving as EORs within that contractual framework. The distinction matters because contractual obligations, including scope, deliverables, and liability, often attach to the DOR even when technical sealing authority resides with individual engineers.
Why the Distinction Matters for MEP Teams
For MEP teams, confusion between EOR and DOR most often arises when professional responsibility and contractual responsibility are assumed to be the same. While the Engineer of Record is responsible for the technical integrity and code compliance of a defined engineering scope, the Designer of Record is typically responsible for delivering that scope under the terms of the contract. When these roles are not clearly differentiated, expectations around coordination, decision-making, and liability can become misaligned.
This distinction becomes especially important on projects that include delegated design, design-build elements, or public-sector procurement requirements. MEP engineers may rely on manufacturer-provided details or specialty consultants, but reliance does not transfer responsibility unless it is explicitly defined. Understanding whether responsibility flows through licensure, contract language, or both helps teams establish appropriate review processes and avoid accountability gaps.
Clear identification of EOR and DOR roles also affects how questions are resolved during construction. RFIs, substitutions, and scope clarifications often hinge on who has authority to interpret design intent versus who is contractually obligated to respond. When roles are clearly defined early, MEP teams can respond consistently and defensibly, reducing the likelihood of disputes or duplicated effort later in the project.
Common Pitfalls
One of the most common pitfalls occurs when delegated design is assumed to transfer Engineer of Record responsibility. While specialty consultants, vendors, or manufacturers may provide calculations or details, the EOR typically remains responsible for ensuring that delegated components align with the overall design intent and applicable codes. When this distinction is not understood, gaps in review and coordination can emerge.
Another frequent issue arises when terminology from government contracting is applied to private-sector projects without clarification. The use of “Designer of Record” outside of its intended contractual context can create confusion about who is responsible for coordination, responses, and decision-making, particularly when multiple firms or disciplines are involved.
Conflicts also occur when contract language, drawing titles, and professional seals do not align. If contractual documents assign responsibility differently than what is implied by the drawings, teams may operate under incorrect assumptions until a dispute forces clarification. These misalignments are often discovered late, when changes are more costly and time-consuming.
Finally, teams sometimes assume that the word “record” carries the same implication across all project types. In practice, “record” can reference professional licensure, contractual accountability, or document custody, depending on context. Failing to clarify which meaning applies can lead to overlapping responsibilities or situations where no party believes they are responsible for a critical decision.
The Takeaway
EOR and DOR are not interchangeable terms. One defines professional responsibility, the other defines contractual accountability. Knowing which applies, and when, helps align expectations across Owners, consultants, and contractors.
At Aethera Engineers, we emphasize role clarity early in the project so responsibility is well defined, coordination is intentional, and MEP systems are delivered with fewer disputes and better outcomes.
