105 Customs and Usages

• Jurisdiction: Arizona

Customs and usages will be used by the courts to resolve ambiguities in contracts, but they cannot be used to create contracts that otherwise would not exist.

Custom and usage may be used to interpret the provisions of construction contracts. Evidence of a habitual or customary practice can be used to interpret whether a contract has been performed and to prove the amount of damages resulting from a contract breach. Arizona courts have implied the principle of custom and usage to determine, for example, whether the phrase “complete installation of heating equipment” includes, by implication, the installation of lead-in pipes, Lenslite Co. v. Zocher, 95 Ariz. 208, 388 P.2d 421 (1964); whether an engineering firm properly performed its contractual obligation to furnish the developer topographical and soil reports by forwarding such reports directly to the designing architect, Gutmacher v. H & J Constr. Co., 101 Ariz. 346, 419 P.2d 525 (1966); and whether...