Tallahassee, FL Accessory Structures: ADU Impact Fees (2026)

Tallahassee replaced its earlier transportation impact fee with a Multimodal Transportation Mobility Fee under Tallahassee-Leon County Concurrency Management. ADU charges include: (1) Mobility Fee based on land-use category and trip generation — ADUs are typically charged at a reduced trip-generation rate compared to a single-family detached home given their smaller size; (2) Stormwater system development charge under the Stormwater Management Ordinance; (3) City of Tallahassee Utilities water and sewer system development (capacity) charges, which can be reduced or waived where the ADU shares an existing service connection with the principal dwelling; (4) Leon County School Impact Fee, collected by the County under interlocal agreement; (5) parks impact fees where applicable. Florida Statute § 163.31801 sets the constitutional and procedural framework for impact fees, requiring rational nexus and rough proportionality. Florida HB 337 (2021) amended the statute to cap impact-fee increases at 50% over four years or 25% over two years, with phased adoption required for higher increases — and the legislature has added further procedural safeguards in subsequent sessions. Local governments must justify any increase with an infrastructure-deficiency study. Property reassessment is performed by the Leon County Property Appraiser after construction, increasing annual ad valorem taxes; the homestead exemption applies only to the principal dwelling.