To be successful in a claim against an architect or engineer, expert testimony is required to support contract claims, as well as professional negligence claims, when the subject matter involves technical or specialized knowledge beyond common lay understanding. A case exemplifying this situation is RTI, LLC v. Pro Engineering, Inc.,
28 N.W.3d 167 (S.D. 2025), and is discussed below.
Background of the Case
RTI, LLC, undertook the construction of a specialized research facility for the animal health industry, which required precise environmental controls. The facility demanded exacting specifications for air filtration, airflow patterns, and pressure differentials between rooms—critical requirements for conducting sensitive animal health research.
RTI essentially acted as its own general contractor, assembling a team that, in addition to various other consulting and construction entities, included designArc ("Architect"), responsible for architectural design and specifications, and Pro Engineering, Inc. ("Engineer"), engaged to design the electrical, plumbing, waste, vent, and domestic water systems, as well as the HVAC and ductwork systems.
Shortly after construction completion, significant operational problems emerged. RTI discovered purported deficiencies related to air pressure control throughout the facility, which was a critical failure given the specialized nature of the research operations.
As to the Architect, RTI alleged that it failed to determine the appropriate ceiling specifications capable of withstanding air pressure fluctuations and failed to recommend ceiling products compliant with the facility's pressure requirements. RTI claimed the suspended ceiling system shifted under air pressure changes and collapsed.
RTI's claims against the Engineer alleged that the HVAC design failed to deliver the contracted-for system performance, specifically noting the inability to control airflow direction and an inadequate capacity to adjust and maintain pressure differentials between rooms.
RTI's lawsuit alleged breach of contract and breach of implied warranties against the Architect, Engineer, and others. As the suit progressed, a fundamental dispute emerged over the need for expert testimony. Both the Architect and Engineer argued that expert testimony was essential to establish the applicable standard of care for the complex design and installation work at issue in RTI's lawsuit.
RTI took the position that expert testimony was unnecessary and argued that the alleged deficiencies were within a layperson's comprehension, but if an expert were required, RTI's CEO, who managed the project, possessed sufficient qualifications to testify. RTI also asserted that the distinction between negligence and contract claims was immaterial, proclaiming: "Whether we call it a negligence claim or breach of contract claim, it's all the same thing."
However, RTI's position would prove fatal to its claims against the Architect and Engineer.
The Court's Analysis
The court initially addressed whether the expert testimony requirement applies differently depending on the legal theory asserted. The answer was unequivocal: no.
The court held that the expert testimony requirement is not limited to professional negligence actions. Rather, it applies with "equal force to a breach of contract claim." In support, the court cited KOKO Dev., LLC v. Phillips & Jordan, Inc.,
101 F.4th 544, 551 (8th Cir. 2024), a construction case arising from North Dakota, which held that both breach of contract and negligence claims required expert testimony.
Under either theory of recovery, whether negligence or breach of contract, expert testimony is required if the subject matter of the allegations does not fall within the common experience and capability of a layperson to judge.
The Ruling as Respects the Architect
Because law of this jurisdiction had not previously addressed whether expert testimony is necessary for claims against architects, the court undertook a comprehensive analysis of this issue of first impression. The court began by noting that courts in other jurisdictions have consistently held that expert testimony is required to establish that an architect's conduct failed to comply with contractual obligations or professional architectural standards.
The court then examined in detail the seminal case of Watson, Watson, Rutland/Architects, Inc. v. Montgomery County Board of Ed.,
559 So. 2d 168 (Ala. 1990), a breach of contract action arising from a leaking roof. The Watson court articulated the rationale for requiring expert testimony even in contract-based claims against architects as follows:
An architect is a "professional," and we are of the opinion that expert testimony was needed…. Just as in cases dealing with an alleged breach of a duty by an attorney, a doctor, or any other professional, unless the breach is so obvious that any reasonable person would see it, then expert testimony is necessary in order to establish the alleged breach. The nature and extent of the duty of an architect … are not matters of common knowledge….
The breach alleged … architectural matters that would not be within the common knowledge of the jurors, yet [Plaintiff] presented no expert testimony regarding the Architect's … deficiencies…. The School Board presented no expert testimony regarding the standard of care imposed within the architectural profession …, and there was no expert evidence that that standard was breached by the Architect.
Applying this holding to RTI's allegations against the Architect, the court concluded that the claims were beyond the common experience or capability of average laypersons. Determining proper ceiling specifications to withstand air pressure fluctuations, selecting appropriate ceiling products for specialized research facilities, and understanding the interaction between architectural elements and HVAC systems all require specialized knowledge that laypersons lack.
Consequently, expert testimony was necessary to establish the obligations owed to RTI under either contract or professional standards, whether the Architect breached those obligations, and whether any breach caused damages to RTI.
Absent expert testimony, the court concluded that RTI could not establish the essential elements of its claims against the Architect. As a result, the lower court properly granted judgment in favor of the Architect.
The Ruling as Respects the Engineer
The court applied similar reasoning to RTI's claims against the Engineer with one important nuance: RTI's claims against the Engineer centered on the HVAC system's ability to control airflow direction and adjust air pressure as required by the facility's specialized research functions. The court acknowledged that, while the concept of airflow direction is within the comprehension of laypersons, the design and equipment necessary to accomplish this type of control are not.
Understanding whether an engineering design properly addresses ventilation, air movement, reverse flow, system balancing, and pressurization requires specialized engineering knowledge, and these are not matters that a jury can evaluate based on common experience.
Without expert testimony to establish that the Engineer "failed to provide ventilation, movement of air, reverse flow, balancing system, [and] pressurizing," RTI could not prove its claims. Again, the court concluded that the lower court properly granted judgment in favor of the Engineer.
The Common Knowledge Exception
However, it is crucial to note that expert testimony is not universally required in claims against design professionals. As the court emphasized, the necessity of expert testimony depends on the nature of the alleged breach. The court said, as with any claims against a professional—whether an architect, an engineer, a lawyer, or a physician—if the failure is so obvious that any reasonable layperson could recognize it as a departure from acceptable standards, expert testimony may be unnecessary.
Conversely, when the alleged breach involves technical matters, industry standards, or professional judgment that falls outside the common knowledge of an ordinary person, expert testimony becomes essential to establish both the applicable standard of care and the defendant's deviation from it.
While this exception exists in theory, the RTI case demonstrates how rarely it applies in practice. Even claims that may seem straightforward, such as a collapsed ceiling or inadequate airflow, frequently involve technical design decisions, material specifications, and system interactions that require expert analysis to evaluate properly.
Takeaways
There are a multitude of lessons to be learned from this case. The following are a few of the most significant for any claim involving a design professional.
Expert testimony is not merely helpful; it is the foundation upon which technical claims are won or lost. Without credible expert witnesses, even meritorious positions become indefensible.
Budget proactively for expert costs.
Identify and prequalify potential experts as soon as possible, particularly those familiar with the practice area and applicable standards.
Consider retaining consulting experts early in disputes to assess case strength before committing to litigation.
Do not (mistakenly) assume pure contractual disputes will not require expert testimony when technical matters are involved. When contracts involve technical deliverables, performance standards, or professional services, expert testimony becomes equally essential to establish whether contract requirements were met, whether industry-standard interpretations of technical specifications, whether causation between alleged breaches and damages, and the reasonableness of contract terms and expectations.
If you are a design professional, document all decisions; contemporary documentation of design rationale provides the expert witness with a narrative thread to defend your decisions. Document why you selected Option A over Options B or Option C. Note budget limitations, client directives, site conditions, or code requirements that shaped decisions.
Courts occasionally permit lay testimony on matters within "common knowledge" without expert qualification, but this exception is extremely narrow in professional liability disputes. Avoid the temptation to believe your case is "obvious enough" to avoid expert costs by relying on the common knowledge exception. If your dispute involves any aspect of professional practice, standards of care, technical specifications, or specialized knowledge, assume you need an expert—period.
Opinions expressed in Expert Commentary articles are those of the author and are not necessarily held by the author's employer or IRMI. Expert Commentary articles and other IRMI Online content do not purport to provide legal, accounting, or other professional advice or opinion. If such advice is needed, consult with your attorney, accountant, or other qualified adviser.
To be successful in a claim against an architect or engineer, expert testimony is required to support contract claims, as well as professional negligence claims, when the subject matter involves technical or specialized knowledge beyond common lay understanding. A case exemplifying this situation is RTI, LLC v. Pro Engineering, Inc., 28 N.W.3d 167 (S.D. 2025), and is discussed below.
Background of the Case
RTI, LLC, undertook the construction of a specialized research facility for the animal health industry, which required precise environmental controls. The facility demanded exacting specifications for air filtration, airflow patterns, and pressure differentials between rooms—critical requirements for conducting sensitive animal health research.
RTI essentially acted as its own general contractor, assembling a team that, in addition to various other consulting and construction entities, included designArc ("Architect"), responsible for architectural design and specifications, and Pro Engineering, Inc. ("Engineer"), engaged to design the electrical, plumbing, waste, vent, and domestic water systems, as well as the HVAC and ductwork systems.
Shortly after construction completion, significant operational problems emerged. RTI discovered purported deficiencies related to air pressure control throughout the facility, which was a critical failure given the specialized nature of the research operations.
As to the Architect, RTI alleged that it failed to determine the appropriate ceiling specifications capable of withstanding air pressure fluctuations and failed to recommend ceiling products compliant with the facility's pressure requirements. RTI claimed the suspended ceiling system shifted under air pressure changes and collapsed.
RTI's claims against the Engineer alleged that the HVAC design failed to deliver the contracted-for system performance, specifically noting the inability to control airflow direction and an inadequate capacity to adjust and maintain pressure differentials between rooms.
RTI's lawsuit alleged breach of contract and breach of implied warranties against the Architect, Engineer, and others. As the suit progressed, a fundamental dispute emerged over the need for expert testimony. Both the Architect and Engineer argued that expert testimony was essential to establish the applicable standard of care for the complex design and installation work at issue in RTI's lawsuit.
RTI took the position that expert testimony was unnecessary and argued that the alleged deficiencies were within a layperson's comprehension, but if an expert were required, RTI's CEO, who managed the project, possessed sufficient qualifications to testify. RTI also asserted that the distinction between negligence and contract claims was immaterial, proclaiming: "Whether we call it a negligence claim or breach of contract claim, it's all the same thing."
However, RTI's position would prove fatal to its claims against the Architect and Engineer.
The Court's Analysis
The court initially addressed whether the expert testimony requirement applies differently depending on the legal theory asserted. The answer was unequivocal: no.
The court held that the expert testimony requirement is not limited to professional negligence actions. Rather, it applies with "equal force to a breach of contract claim." In support, the court cited KOKO Dev., LLC v. Phillips & Jordan, Inc., 101 F.4th 544, 551 (8th Cir. 2024), a construction case arising from North Dakota, which held that both breach of contract and negligence claims required expert testimony.
Under either theory of recovery, whether negligence or breach of contract, expert testimony is required if the subject matter of the allegations does not fall within the common experience and capability of a layperson to judge.
The Ruling as Respects the Architect
Because law of this jurisdiction had not previously addressed whether expert testimony is necessary for claims against architects, the court undertook a comprehensive analysis of this issue of first impression. The court began by noting that courts in other jurisdictions have consistently held that expert testimony is required to establish that an architect's conduct failed to comply with contractual obligations or professional architectural standards.
The court then examined in detail the seminal case of Watson, Watson, Rutland/Architects, Inc. v. Montgomery County Board of Ed., 559 So. 2d 168 (Ala. 1990), a breach of contract action arising from a leaking roof. The Watson court articulated the rationale for requiring expert testimony even in contract-based claims against architects as follows:
Applying this holding to RTI's allegations against the Architect, the court concluded that the claims were beyond the common experience or capability of average laypersons. Determining proper ceiling specifications to withstand air pressure fluctuations, selecting appropriate ceiling products for specialized research facilities, and understanding the interaction between architectural elements and HVAC systems all require specialized knowledge that laypersons lack.
Consequently, expert testimony was necessary to establish the obligations owed to RTI under either contract or professional standards, whether the Architect breached those obligations, and whether any breach caused damages to RTI.
Absent expert testimony, the court concluded that RTI could not establish the essential elements of its claims against the Architect. As a result, the lower court properly granted judgment in favor of the Architect.
The Ruling as Respects the Engineer
The court applied similar reasoning to RTI's claims against the Engineer with one important nuance: RTI's claims against the Engineer centered on the HVAC system's ability to control airflow direction and adjust air pressure as required by the facility's specialized research functions. The court acknowledged that, while the concept of airflow direction is within the comprehension of laypersons, the design and equipment necessary to accomplish this type of control are not.
Understanding whether an engineering design properly addresses ventilation, air movement, reverse flow, system balancing, and pressurization requires specialized engineering knowledge, and these are not matters that a jury can evaluate based on common experience.
Without expert testimony to establish that the Engineer "failed to provide ventilation, movement of air, reverse flow, balancing system, [and] pressurizing," RTI could not prove its claims. Again, the court concluded that the lower court properly granted judgment in favor of the Engineer.
The Common Knowledge Exception
However, it is crucial to note that expert testimony is not universally required in claims against design professionals. As the court emphasized, the necessity of expert testimony depends on the nature of the alleged breach. The court said, as with any claims against a professional—whether an architect, an engineer, a lawyer, or a physician—if the failure is so obvious that any reasonable layperson could recognize it as a departure from acceptable standards, expert testimony may be unnecessary.
Conversely, when the alleged breach involves technical matters, industry standards, or professional judgment that falls outside the common knowledge of an ordinary person, expert testimony becomes essential to establish both the applicable standard of care and the defendant's deviation from it.
While this exception exists in theory, the RTI case demonstrates how rarely it applies in practice. Even claims that may seem straightforward, such as a collapsed ceiling or inadequate airflow, frequently involve technical design decisions, material specifications, and system interactions that require expert analysis to evaluate properly.
Takeaways
There are a multitude of lessons to be learned from this case. The following are a few of the most significant for any claim involving a design professional.
Opinions expressed in Expert Commentary articles are those of the author and are not necessarily held by the author's employer or IRMI. Expert Commentary articles and other IRMI Online content do not purport to provide legal, accounting, or other professional advice or opinion. If such advice is needed, consult with your attorney, accountant, or other qualified adviser.