San Clemente, CA Accessory Structures: ADU Impact Fees (2026)

270(D)(4) of the San Clemente Municipal Code sets impact and utility fees for accessory dwelling units approved either as building-permit-only ADUs or under a separate ADU permit. a, no impact fee applies to an ADU smaller than 750 square feet; the code defines 'impact fee' here as a fee under the state Mitigation Fee Act, Government Code Section 66000(b), or the Quimby Act, Government Code Section 66477, and specifically excludes water and sewer connection fees or capacity charges from that exemption. For an ADU of 750 square feet or larger, any impact fee that does apply must be charged proportionately, calculated as the ADU's floor area divided by the primary dwelling's floor area, multiplied by the typical fee charged for a new dwelling, rather than the full flat fee a new house would pay.

b: an ADU built alongside a new single-family home needs its own utility connection and pays the normal connection fee and capacity charge, but a converted ADU on a single-family lot created within existing space is not required to have a new or separate utility connection or to pay any connection fee or capacity charge at all. Any other ADU needing a new utility connection is charged a connection fee or capacity charge proportionate to the burden it adds, measured by floor area or drainage-fixture units under the Uniform Plumbing Code, and the City-charged portion cannot exceed the reasonable cost of providing that service.