Section 15-36-100(A)(3) Permits Cross-Discipline Expert Affidavits—and Limits Claims to What the Affiant Will Actually Support

I. Introduction

In Charles Blanchard Construction Corp., Inc. v. 480 King Street, LLC (S.C. Sup. Ct. Jan. 21, 2026), the Supreme Court of South Carolina interpreted key provisions of the South Carolina Frivolous Civil Proceedings Sanctions Act (the “Act”), particularly S.C. Code Ann. § 15-36-100, which requires an expert affidavit to accompany (or follow within a limited grace period) a complaint alleging professional negligence against certain licensed professionals—including architects.

The dispute arose from a project in which 480 King Street, LLC (“480 King”) retained Glick/Boehm & Associates, Inc. (“GBA”), an architectural firm, to design a stair tower and to provide construction/contract administration services during the build. 480 King asserted negligence, breach of contract, and breach of warranty claims. Because a limitations deadline loomed, it did not file the required affidavit with the complaint (nor within the statutory 45-day window). After initial motion practice, the circuit court allowed an affidavit to be filed late.

480 King then filed an affidavit by a professional engineer, Louis Hackney. On its face, the affidavit addressed both design-related deficiencies and construction administration failures. Years later, however, deposition testimony revealed Hackney would not offer opinions about an architect’s design standard of care, and he framed his opinions as limited to construction-phase/administration services. GBA moved again to dismiss—this time relying on the deposition testimony to argue the affidavit was legally insufficient.

The key issues were: (1) whether GBA could challenge affidavit sufficiency years later; (2) whether the Act requires the affiant to be in the same profession as the defendant; (3) whether Hackney’s affidavit supported claims for negligent design versus negligent construction administration; and (4) whether breach of contract and warranty claims were subject to dismissal for failure to satisfy the affidavit requirement.

II. Summary of the Opinion

The Supreme Court affirmed in part and reversed in part. It held:

No same-profession requirement under § 15-36-100(A)(3): The Act permits an expert affidavit from a non-architect if the affiant has “scientific, technical, or other specialized knowledge” and the affidavit explains credentials and why the affiant is qualified.
Negligent construction administration survives: Hackney’s affidavit remained sufficient under § 15-36-100(A)(3) for claims tied to construction administration services.
Negligent architectural design is dismissed: Because Hackney confirmed he would not offer design-standard-of-care opinions, 480 King lacked a qualifying affidavit for negligent design; no remand was warranted.
Negligent supervision is subsumed: Any negligent supervision theory was treated as part of (and not separate from) negligent construction administration.
Contract and warranty claims are “grounded in negligence” and rise/fall accordingly: The breach of contract claim could proceed only to the extent it concerned construction administration; the design-based portion was dismissed. The breach of warranty claim (pleaded as design-based) was dismissed in full.
Late affidavit challenge allowed on these facts: Despite delay and an earlier period to contest sufficiency, the Court agreed GBA did not waive the challenge given what emerged in depositions.

Justice Few concurred, emphasizing a narrower view: the General Assembly likely intended affidavit-validity fights to occur promptly after filing, but this case was “truly unique” because the theory of design causation was never articulated and because deposition testimony could not be reconciled with the affidavit.

III. Analysis

A. Precedents Cited

Doe v. Bishop of Charleston and Doe v. Marion: The Court relied on these cases for the Rule 12(b)(6) dismissal standard—dismissal is improper if the alleged facts and reasonable inferences, viewed favorably to the plaintiff, allow relief on any theory. This framing mattered because the case nominally arose under Rule 12(b)(6), but involved evidence beyond the pleadings.
Kitchen Planners, LLC v. Friedman: Cited for the Rule 56 summary judgment standard (“no genuine issue as to any material fact” and entitlement to judgment as a matter of law), reinforcing the Court’s point that its outcome would be the same whether analyzed under Rule 12(b)(6) or Rule 56 due to the decisive statutory interpretation and the undisputed effect of deposition testimony.
Grier v. AMISUB of S.C., Inc., CFRE, LLC v. Greenville Cnty. Assessor, and Hodges v. Rainey: These authorities supplied the Court’s interpretive methodology: statutory interpretation is reviewed de novo; legislative intent is best evidenced by statutory text; courts must give effect to expressed legislative intent. This method was central to rejecting a “bright-line” same-profession rule not found in the text.
Eades v. Palmetto Cardiovascular & Thoracic, PA: The Court used Eades as the key analog to validate cross-specialty (and, here, cross-profession) expert qualification under § 15-36-100. In Eades, a vascular/critical care surgeon could opine on the standard of care applicable to emergency and primary care physicians based on specialized knowledge explained in the affidavit. The Court also rejected GBA’s attempt to confine Eades to medical malpractice actions, extending the logic to architecture/professional negligence under the Act.
Skydive Myrtle Beach, Inc. v. Horry Cnty.: Invoked in a footnote to note constraints on dismissals “with prejudice” under Rule 12(b)(6) absent a meaningful opportunity to amend. The Court found it inapplicable because 480 King did not seek leave to amend its contract/warranty pleading.
Charles Blanchard Construction Corp. v. 480 King Street, LLC (Ct. App. 2024): The Supreme Court reviewed and partially agreed with the court of appeals, affirming the survival of the construction administration negligence theory, but reversing remands where the affidavit record could not support design and warranty theories.

B. Legal Reasoning

1. The Act’s definition of “expert witness” creates three alternative qualification paths

The Court’s doctrinal center is its reading of § 15-36-100(A). While subsections (A)(1) and (A)(2) impose licensing/board-certification (or practice/teaching) criteria that often align with the defendant’s professional identity, the Court treated § 15-36-100(A)(3) as an independent, meaningful alternative.

The Court reasoned that adopting GBA’s “same-profession” requirement would effectively nullify § 15-36-100(A)(3). Because (A)(3) expressly covers an “individual not covered by subsections (A)(1) or (2)” with specialized knowledge that can assist the factfinder, the legislature necessarily contemplated expert affidavits from professionals outside the defendant’s discipline—so long as the affidavit explains credentials and the basis for qualification.

2. Facial sufficiency matters—but deposition testimony can expose that the affidavit does not actually support a pleaded theory

Hackney’s affidavit was facially detailed: it described his experience and asserted deviations relating to both design documentation and construction administration. However, the later deposition record became dispositive on claim-splitting: Hackney ultimately disclaimed offering opinions on an architect’s standard of care for design and limited his opinions to construction-phase/administration services.

The Court treated this as a practical failure of the statutory condition precedent for the design-negligence claim: even if a non-architect could theoretically qualify under (A)(3) to opine on architectural design, this affiant would not do so; therefore, 480 King “has no claim” for negligent design because it “did not submit an affidavit from an expert as to architectural design.” This framing is important: the defect was not merely technical; it was substantive and irremediable on the existing record.

3. Construction administration is treated as a distinct professional-negligence theory with its own standard-of-care proof

The Court accepted 480 King’s core pleading premise: GBA served both as designer and construction contract administrator. It then analyzed affidavit sufficiency theory-by-theory, not defendant-by-defendant: Hackney had experience in “contract administration services” and explicitly alleged deviations in that arena. His deposition testimony remained consistent with that portion of the affidavit, so the affidavit satisfied the Act for that slice of the case.

4. “Grounded in negligence” contract and warranty claims: partial survival depends on which professional-negligence theory is properly supported

The Court reaffirmed an often-litigated boundary: plaintiffs cannot plead around the affidavit requirement by re-labeling professional-negligence content as “contract” or “warranty.” Here, the breach of contract particulars were “identical” to the negligence particulars; thus, the contract claim was “indisputably grounded in negligence” and subject to the affidavit regime.

The result was granular:

Breach of contract: proceeds only insofar as it concerns construction administration (the supported negligence theory); dismissed as to design (unsupported).
Breach of warranty: dismissed because 480 King pleaded it as design-based (“failing to design the stair tower free from defects…”), and design was unsupported by a qualifying affidavit. Incorporation of the contract allegations reinforced that it was grounded in negligence.

5. Timing/waiver of challenges: a pragmatic, fact-specific allowance—tempered by the concurrence

The Court agreed with the court of appeals that GBA did not waive its ability to challenge the affidavit years later, despite an earlier court-imposed period to contest sufficiency. The decision is explicitly narrow (“Under the facts of this case…”).

Justice Few’s concurrence adds an interpretive caution: § 15-36-100 likely contemplates prompt challenges after the affidavit is filed, but the case was exceptional because (i) the third-party complaint never coherently articulated design causation, and (ii) the expert’s deposition testimony was irreconcilable with the affidavit, meaning the defendant lacked a reasonable early basis to contest what appeared facially adequate.

C. Impact

Broader expert pool under § 15-36-100(A)(3): The Court’s reading strengthens (A)(3) as a real avenue for qualification beyond licensing/board-certification criteria, potentially easing affidavit procurement in multi-disciplinary construction and engineering disputes.
Claim-by-claim affidavit sufficiency: Plaintiffs alleging multiple professional service failures (e.g., design vs. construction administration) should expect courts to parse affidavit support by theory. A single affiant may support only some claims; unsupported claims may be dismissed without remand if deposition testimony forecloses the required standard-of-care opinions.
Pleading strategy for contract/warranty claims: The ruling reinforces that contract/warranty counts mirroring negligence particulars will be treated as “grounded in negligence,” bringing them within § 15-36-100—at least to the extent the underlying duty sounds in professional standard of care.
Procedural risk management: Although the majority permitted a late challenge here, the concurrence signals future litigants should not assume challenges can be deferred. Defendants may still feel pressure to contest early; plaintiffs should anticipate that later discovery may reopen affidavit adequacy disputes where affidavit assertions and testimony diverge.

IV. Complex Concepts Simplified

“Expert affidavit requirement” (§ 15-36-100(B)): In professional-negligence cases against listed professionals, the plaintiff must provide an early expert affidavit stating at least one negligent act/omission and its factual basis. It functions as a gatekeeping mechanism to deter unsupported suits.
Three ways to be an “expert witness” under the Act (§ 15-36-100(A)): (A)(1) and (A)(2) focus on licensing and board certification (or equivalent practice/teaching experience), while (A)(3) allows other specialized-knowledge experts if credentials and qualification are explained.
Rule 12(b)(6) vs. Rule 56 conversion: A 12(b)(6) motion tests the pleadings; if the court considers matters outside the pleadings (like deposition excerpts) and does not exclude them, the motion is treated like summary judgment under Rule 56.
“Grounded in negligence”: Even if labeled “contract” or “warranty,” a claim may be treated as negligence-based when it relies on the same allegations as professional negligence—triggering the affidavit requirement.
“Subsumed” claims: A separate label (e.g., negligent supervision) may not survive as an independent theory if its substance is already encompassed within another claim (here, negligent construction administration).

V. Conclusion

The decision cements a significant construction of the Act: § 15-36-100(A)(3) authorizes cross-discipline expert affidavits when specialized knowledge is explained, rejecting an implied same-profession rule. But the Court paired that expansion with a limiting principle: a plaintiff may proceed only on the professional-negligence theories the affidavit—and the affiant’s actual intended opinions—truly support. As a result, construction administration claims survived, while design and design-based warranty theories did not.

The opinion also clarifies that contract and warranty claims mirroring negligence particulars remain subject to § 15-36-100, and it signals (especially through the concurrence) that while late challenges to affidavit sufficiency may be allowed in exceptional circumstances, the statute’s structure likely favors prompt litigation of affidavit validity in the ordinary case.