St. Petersburg, FL Accessory Structures: ADU Impact Fees (2026)

Municipal impact fees in Florida are governed by the Florida Impact Fee Act at Fla. Stat. §163.31801, which requires a rational nexus between fees and the cost of new infrastructure attributable to the development. St. Petersburg's impact-fee categories include transportation (multimodal mobility), parks and recreation, water and wastewater (Public Utilities Department), and fire-rescue service. Pinellas County collects a separate school impact fee through the Pinellas County School Board. ADU rates scale to floor area and are typically lower than for new primary dwellings. Where an ADU shares the existing water service and sewer lateral with the principal dwelling, water and wastewater impact fees are commonly reduced or waived; a separate meter or service triggers full connection charges through the City of St. Petersburg Water Resources Department. Florida HB 337 (2021) amended §163.31801 to cap annual impact-fee increases — generally 25% over two years or 50% over four years with phased adoption, plus a study and notice requirement. St. Petersburg standard building, electrical, plumbing, and mechanical permit fees calculated on construction valuation also apply. Following construction, the Pinellas County Property Appraiser will reassess the parcel and the ad valorem property tax on Pinellas County tax bills will reflect the added improvement value (homestead exemption under Fla. Stat. §196.031 applies only to one primary residence).