Shoen

*1114 When a landowner grants someone permission to use her land, she generally retains the right to revoke that license at any time. ( Emerson v. Bergin (1888) 76 Cal. 197 , 201, 18 P. 264 .) The landowner may nevertheless be estopped from revoking that license-and the license will accordingly become irrevocable for "so long a time as the nature of it calls for"-if the person using the land has "expended money[ ] or its equivalent in labor" improving the land "in the execution of the license." ( Cooke v. Ramponi (1952) 38 Cal.2d 282 , 286, 239 P.2d 638 ( Cooke ); Stoner v. Zucker (1906) 148 Cal. 516 , 520, 83 P. 808 ( Stoner ).) Critically, however, the expenditure of money or labor can make a license irrevocable only if that expenditure is " 'substantial,' " "considerable" or "great." ( Richardson v. Franc (2015) 233 Cal.App.4th 744 , 756, 182 Cal.Rptr.3d 853 ( Richardson ); Dinsmore v. Renfroe (1924) 66 Cal.App. 207 , 211-212, 225 P. 886 ( Dinsmore ); Stepp v. Williams (1921) 52 Cal.App. 237 , 240, 257, 198 P. 661 ( Stepp ).) Here, we conclude that the trial court's grant of an irrevocable license was an abuse of discretion because the court construed the "substantial…