Mutual Conduct Can Waive Written Change-Order Clauses (Even with “No-Waiver-Except-Writing” Language) and Permit Equitable Recovery for Extra-Contract Work

1. Introduction

RJH Builders, LLC v. Robert Thistle & a. (N.H. June 2, 2026) arises from a fixed-price custom-home construction project that deteriorated after a series of owner-requested modifications were made without the contract’s formal written change-order process. The plaintiff, RJH Builders, LLC (RJH), sued the homeowners, Robert and Priscilla Thistle (the Thistles), after the Thistles withheld authorization for a bank disbursement tied to an inspection milestone (Inspection #4), and RJH stopped work.

On appeal, the Thistles challenged three central rulings: (1) allowing RJH to file a late answer asserting waiver as an affirmative defense to the Thistles’ counterclaim; (2) finding the parties waived the construction contract’s written change-order provision notwithstanding contract language requiring written waivers and disclaiming waiver by non-enforcement; and (3) awarding RJH equitable damages (quantum meruit/unjust enrichment) for labor and materials, including extras reflected in disputed invoices.

The Supreme Court of New Hampshire affirmed in an order issued under Sup. Ct. R. 20(3).

2. Summary of the Opinion

  • Late answer/waiver defense allowed: The trial court acted within its discretion to accept RJH’s late-filed answer under Super. Ct. R. 1(d), given the parties litigated as if the counterclaim would be tried and the Thistles never sought default.
  • Waiver of change-order provision affirmed: The trial court’s finding that both parties, by repeated conduct, waived the written change-order requirement (and related “writing required” and “no waiver by non-enforcement” clauses) was not clearly erroneous.
  • Equitable damages affirmed: Even where the court found no breach of the written Construction Agreement by RJH, it could award equitable recovery for labor/materials substantially completed and for benefits outside the contract’s scope requested by the Thistles.
  • Appellate-record and briefing limits: Certain damages challenges failed because the Thistles did not supply a complete record of exhibits; other arguments were deemed insufficiently developed.

3. Analysis

3.1. Precedents Cited

A. Discretion to relax procedural rules; late pleadings; prejudice

  • Anna H. Cardone Revocable Trust v. Cardone, 160 N.H. 521 (2010)
    Used for the governing standard: trial courts have “broad discretion” to waive their rules, and appellate review asks whether the decision was an “unsustainable exercise of discretion.” This anchored affirmance of the trial court’s “good cause” determination for accepting the late answer.
  • Kalil v. Town of Dummer Zoning Bd. of Adjustment, 159 N.H. 725 (2010)
    Cited for New Hampshire’s preference for “justice over procedural technicalities,” reinforcing that allowing the late waiver defense was not reversible absent demonstrated prejudice or untenable reasoning.
  • State v. Crooker, 139 N.H. 226 (1994)
    Invoked by analogy on prejudice: a party complaining of late disclosure may mitigate prejudice by requesting a continuance. Here, after the waiver defense was allowed and trial continued months later, the Thistles did not seek to reopen discovery—undercutting their prejudice claim.
  • Walters v. Performant Recovery, Inc., 124 F. Supp. 3d 75 (D. Conn. 2015)
    Used as a “cf.” comparison for notice pleading of affirmative defenses. The court distinguished Walters (where waiver pleading was fact-free and prejudicial) by pointing to the Thistles’ counterclaim, RJH’s answer, and RJH’s objection to the motion to strike as collectively providing adequate notice of the waiver theory.

B. Contract waiver (express/implied) and standards of review

  • Private Jet Servs. Grp. v. Tauck, Inc., 176 N.H. 553 (2024), 2024 N.H. 20
    Supplies the definition of waiver as intentional relinquishment of a known right and confirms waiver may be inferred from conduct. This framed the court’s acceptance that repeated, mutual departure from the change-order process can amount to waiver.
  • Prime Financial Group v. Masters, 141 N.H. 33 (1996)
    Reinforces that waiver of contract terms may be express or implied and must be determined from case-specific facts and conduct. The opinion used Prime Financial Group to validate the trial court’s conduct-based inference of waiver.
  • Renovest Co. v. Hodges Development Corp., 135 N.H. 72 (1991)
    Provides the appellate lens: implied waiver is a question of fact; the Supreme Court will not overturn unless “clearly erroneous.” This was critical because the Thistles’ challenge targeted factual inferences drawn from the parties’ course of performance.
  • Carpenter v. Southbay Homeowners Ass'n, 23 N.W.3d 118 (N.D. 2025)
    Cited to illustrate the type of “no waiver in one instance does not waive future breaches” clause that was absent here. The New Hampshire court used this contrast to support the inference that repeated non-use of the change-order mechanism could mature into waiver, rather than being confined to isolated departures.

C. Equitable remedies and limits on appellate review

  • Clapp v. Goffstown Sch. Dist., 159 N.H. 206 (2009)
    Establishes the “unsustainable exercise of discretion” standard for reviewing equitable damage awards. This made the Thistles’ damages challenge an uphill battle absent a clearly unreasonable or prejudicial ruling.
  • Axenics, Inc. v. Turner Constr. Co., 164 N.H. 659 (2013)
    Provides the doctrinal bridge that unjust enrichment can be available between contracting parties when the benefit conferred falls “outside the scope of the contract.” The court relied on this to uphold compensation for owner-requested extras not included in the plans/specifications.
  • Osman v. Lin, 169 N.H. 329 (2016)
    Central to the record-based rejection of some damages objections: the appellant bears the burden of providing a sufficient record; absent a complete record, the court presumes support for the trial court’s findings.
  • State v. Blackmer, 149 N.H. 47 (2003)
    Used to decline review of arguments not adequately developed on appeal—here, claims about credits for various owner-paid vendor items.
  • McNeal v. Lebel, 157 N.H. 458 (2008)
    Supports two propositions: deference to supported factual findings and allowance of recovery for the value of work even if performance was not perfect or complete, particularly where substantial completion and punch-list practices explain remaining items.
  • Vogel v. Vogel, 137 N.H. 321 (1993)
    Cited to justify dispensing with discussion of remaining arguments that did not warrant further analysis.

3.2. Legal Reasoning

A. Late-filed answer asserting waiver: “good cause” and lack of prejudice

The court treated the late answer as a case-management issue governed by Super. Ct. R. 9(a) (timely answer requirement) and Super. Ct. R. 1(d) (authority to waive rules for good cause and justice). Two facts drove the “good cause” analysis: (1) both sides litigated with the expectation the counterclaim would be tried; and (2) the Thistles never sought default on the counterclaim. The Supreme Court also rejected the notice/prejudice attack, emphasizing that the combined pleadings and motion practice conveyed the factual basis for waiver, and that the Thistles neither sought to reopen discovery nor otherwise demonstrated concrete prejudice after the trial continuance.

B. Waiver of the written change-order provision despite “writing-only waiver” and “no waiver by non-enforcement” clauses

The contract contained provisions aimed at preventing informal modifications: paragraph 17 required amendments/waivers to be in a writing signed by the parties, and paragraph 24(b) stated that failure to insist on strict compliance would not constitute waiver. The trial court nevertheless found the parties’ course of performance waived both the writing requirement and the change-order substance.

The Supreme Court affirmed because the waiver finding was grounded in repeated, mutual, and comprehensive noncompliance—not a one-sided lapse or a single instance of leniency. The change-order clause imposed reciprocal protections: owners receive advance written cost/delay disclosure; the contractor receives upfront payment for extras. Yet, over many change requests, neither party invoked any part of the mechanism. The court highlighted:

  • informal change requests by the Thistles during construction;
  • RJH’s performance of extra work without prior written change orders or advance payment;
  • issuance and payment of Invoice #398 for extra work mid-project, signaling an operative practice of post hoc billing rather than signed change orders;
  • continued extras leading to Invoice #404, again without written change orders.

Critically, the court characterized this pattern as conduct “justifying an inference” that the parties intended to relinquish the right to enforce the formal change-order regime, and it distinguished “mere failure to insist upon strict compliance” from wholesale abandonment of the process. The absence of a clause expressly stating that waiver in one instance is not waiver in later instances further supported the inference that the parties’ repeated departures could accumulate into waiver.

C. Equitable recovery for extra-contract work and substantial completion at a loan-draw milestone

Although the trial court found RJH did not prove a breach of the written Construction Agreement, it awarded equitable damages for labor and materials under theories including unjust enrichment/quantum meruit (and an oral contract theory), concluding the measure of recovery would be the same.

The Supreme Court upheld the award on two key rationales:

  • Benefits outside the contract’s scope: The trial court found multiple items were outside the contract plans/specifications—e.g., dormer/windows, finishing the “unfinished” bonus room, custom stairs/closets, extra crown molding, door changes, and other upgrades. Under Axenics, Inc. v. Turner Constr. Co., unjust enrichment is available between parties to a contract where the benefit is outside the contract’s scope.
  • Substantial completion for Inspection #4 work: The court credited evidence that remaining deficiencies (e.g., siding repairs, porch/deck finishing details) resembled punch-list items typically addressed at the end of a project, supporting the factual finding of substantial completion for the limited work RJH claimed at that milestone. McNeal v. Lebel supported recovery for the value of work even where some correction/completion may remain.

The Thistles’ itemized damages/credit challenges also faltered procedurally: without a complete set of trial exhibits in the appellate record, Osman v. Lin required the presumption that the record supported the trial court’s findings.

3.3. Impact

A. Construction-contract administration in New Hampshire

The decision underscores that rigid written change-order clauses can be waived by consistent course of performance, even where the contract includes “no waiver except in writing” and “no waiver by failure to insist” language. For contractors and owners, the practical implication is stark: if both sides repeatedly operate outside the written process, a court may treat the formal mechanism as abandoned, shifting disputes from “noncompliance with change-order paperwork” to fact-intensive questions about scope, requests, value, and benefit.

B. Litigation practice: late defenses and the importance of prejudice

The order reinforces that New Hampshire trial courts have substantial flexibility to permit late pleadings when the case has been litigated on the assumption issues will be tried—and that prejudice must be concrete. Parties opposing late defenses should create a record of specific discovery they would have pursued and should timely seek targeted relief (continuance, reopened discovery) to preserve prejudice arguments.

C. Remedies: equitable recovery alongside (or instead of) contract claims

For construction disputes, the opinion highlights a common path to recovery when paperwork is imperfect: equitable remedies can compensate for extras outside the contract’s scope and for substantially completed work, subject to proof of value and benefit conferred. Conversely, owners disputing extras must focus on scope (what the plans/specs required), authorization (what was requested), and valuation (what was reasonable), while ensuring a complete appellate record if challenging the trial court’s calculations.

4. Complex Concepts Simplified

  • Change order provision: A contract mechanism requiring written approval for deviations from agreed plans/specs, typically documenting price and schedule effects.
  • Waiver (express vs. implied): Giving up a contractual right. Express waiver is stated; implied waiver is inferred from conduct (e.g., repeatedly ignoring a contract requirement).
  • “No waiver except in writing” / “no waiver by non-enforcement” clauses: Terms intended to prevent informal waiver. This case illustrates they may not be foolproof where both parties consistently abandon the contract’s prescribed process.
  • Quantum meruit / unjust enrichment: Equitable doctrines allowing compensation for the value of benefits conferred where it would be unfair for the recipient to keep them without paying—particularly for work outside the contract’s scope.
  • Substantial completion: Work is sufficiently complete for its intended use, with remaining items treated as punch-list corrections rather than nonperformance.
  • Standards of review:
    • Clearly erroneous (fact findings like implied waiver): appellate court defers unless the finding lacks evidentiary support.
    • Unsustainable exercise of discretion (procedural rulings/equitable damages): reversal only if the decision is unreasonable/untenable and prejudicial.

5. Conclusion

RJH Builders, LLC v. Robert Thistle & a. confirms that, in New Hampshire, a written change-order regime—even bolstered by clauses requiring written waivers and disclaiming waiver by non-enforcement—can be waived through sustained, mutual course of conduct. The order also illustrates the judiciary’s preference for adjudicating disputes on their merits over technical defaults and reaffirms the availability of equitable recovery for extra-contract benefits and substantially completed work. Finally, it serves as a cautionary appellate lesson: incomplete records and underdeveloped arguments can be dispositive, regardless of the underlying merits of a damages challenge.