TMS Lighting Ltd. v. KJS Transport Inc., 2014 ONCA 1:
 It is well-established that where the absence of evidence renders it impossible to assess damages, a plaintiff may be entitled to only nominal damages. Goldfarb, for example, says so. But this is not invariably the case. Where a plaintiff proves a substantial loss and the trial judge errs in the assessment of damages arising from that loss, the interests of justice may necessitate a new trial on damages. Although the quantification of damages flowing from the established loss may prove difficult, nonetheless the injured plaintiff is entitled to compensation.
 Goldfarb itself is a case in point. Goldfarb involved a claim for damages for breach of fiduciary duty advanced by the client of a law firm against the firm and the involved firm lawyer. This court held that there was inadequate cogent evidence to support the substantial award of damages made by the trial judge. Justice Finlayson explained, at para. 67:
[The plaintiff/client] failed to prove the losses through appropriate evidence. The trial judge's award of damage is speculative at best, and does not reflect with much precision real losses flowing from the breach, notwithstanding that the plaintiff bore the burden of proving the losses in the normal course.
 Notwithstanding that the proffer of relevant evidence was "fully within the control of [the plaintiff]", the Goldfarb court rejected the remedy of nominal damages and concluded that a new assessment of damages was necessary because the plaintiff had demonstrated a substantial personal loss although evidence proving the quantum of that loss was lacking: Goldfarb at paras. 80, 83 and 84. See also Rosenhek v. Windsor Regional Hospital, 2010 ONCA 13, 257 O.A.C. 283, at paras. 37-38, leave to appeal to S.C.C. refused,  S.C.C.A. No. 89.
 This reasoning is apposite here. On the trial judge's findings, the respondents suffered a substantial and unreasonable interference with the use and enjoyment of their lands, as well as trespass to those lands. The appellants' nuisance and trespass were neither trivial nor transitory. To the contrary, they occurred over a sustained period and interfered, to a significant extent, with the respondents' use and enjoyment of their lands for the purpose of TMS's manufacturing operations. For approximately five years, disruption of TMS's manufacturing operations led to reduced business productivity. This is a real wrong, which caused real loss.
 Damages, including damages for loss of revenues or profits, may be measured in various ways including, where appropriate, based on expert opinion evidence. That the manner of proof of lost productivity damages posited by the respondents at trial failed, does not mean that no proof is available. In all the circumstances, in my view, a new assessment of TMS's lost productivity damages arising from the appellants' proven nuisance and trespass is required in the interests of justice.