What is the standard of review for an award of attorney fees under section 1021.5?

The normal standard of review for an award of attorney fees under section 1021.5 is abuse of discretion. (Connerly v. State Personnel Bd. (2006) 37 Cal.4th 1169, 1175.) This deferential standard of review applies where factual questions predominate the motion for an award of attorney fees. Situations arise, however, where the decision on the motion for attorney fees is based on the construction and application of the statutory criteria to facts that are largely undisputed. (Ibid.) Those situations involve a question of law and are subject to de novo review by the appellate court. (Id. at pp. 1175-1176; see Protect Our Water v. County of Merced (2005) 130 Cal.App.4th 488, 497 [this court reversed trial court, concluding as a matter of law that all criteria for award of attorney fees under 1021.5 had been satisfied].)