Hesperia, CA Accessory Structures: ADU Impact Fees (2026)

California Gov. Code 66315 (formerly Gov. Code 65852.2(f)(3)) bars Hesperia from imposing any impact fee on an ADU of less than 750 square feet. For ADUs of 750 sq ft or larger, Gov. Code 66315(c) limits impact fees to amounts proportional in size to the primary dwelling unit's square footage - Hesperia cannot charge full single-family impact fees on the ADU. Building permit and plan check fees are still charged but must reflect actual permit-processing costs rather than capital-facility impact fees. School district fees under California Education Code 17620 may still apply to ADUs over 500 sq ft, as those are imposed by the local school districts (Hesperia Unified School District) and are not city fees. Water/sewer connection fees from the Mojave Water Agency and Hesperia Water District / Victor Valley Wastewater Reclamation Authority may apply, though Gov. Code 66315(e) prohibits charging more than the actual cost of the connection for ADUs under 750 sq ft. The Mojave Desert location of Hesperia means water capacity is a constrained resource and connection fees can be material - confirm current schedules with the city utility office before applying.