Tennessee's wealthiest county and one of the fastest-growing in the Southeast — home to a uniquely layered three-part development fee structure that can exceed $16,000 per new home permit.
Williamson County is consistently ranked among the nation's highest-income and fastest-growing counties. Anchored by the city of Franklin to the south of Nashville, the county has seen its household count grow by more than 55% between 2010 and 2025 — a pace far outstripping the statewide average of 17%. A November 2025 housing study projected a shortfall of more than 10,000 units by 2030, underscoring just how acute development pressure remains.
The county's housing stock of 133,421 units leans heavily toward detached single-family homes, which account for roughly 72% of the total. Median home values as reported by the U.S. Census Bureau stood at $777,800 as of 2023, but active resale listings tracked by Redfin reached a median of approximately $975,000 in late 2025. Typical new construction in the county runs 2,800–3,000 square feet or larger.
For developers and builders, Williamson County's fee environment is the most complex and most costly in Middle Tennessee. Every new residential building permit triggers two county-wide Adequate Facilities Taxes totaling $2.00 per square foot, plus a separately calculated Education Impact Fee that varies by home size and school district location. Together, these three charges can easily exceed $16,000 on a single large-lot permit — and that is before any additional city-level fees within Franklin, Brentwood, or Nolensville.
The Education Impact Fee — adopted by the County Commission in November 2016 and upheld through litigation by the Tennessee Court of Appeals in 2020 — is recalculated every three years by independent consultants. In February 2025, commissioners authorized a new study to evaluate whether increasing the Adequate Facilities Tax would require offsetting credits against the Education Impact Fee rate, signaling potential changes ahead.
Williamson County is home to six incorporated cities and towns: Brentwood, Fairview, Franklin, Nolensville, Spring Hill, and Thompson's Station. Each municipality operates its own building and planning department and may levy city-level fees on top of the county-wide charges — making it essential for builders to verify the full fee stack for the specific jurisdiction in which a project is located.
This is an estimate only. Fees often change on an annual basis. Contact each municipality to confirm before finalizing your estimates. See an error? Report it here
Local reporting and public records covering Williamson County's development fee landscape.
A study by Bowen National Research presented at the Williamson Inc. Keys to Housing event found that Williamson County's household count grew 55% between 2010 and 2025 — triple the statewide rate. The county is projected to need more than 10,000 additional units by 2030, with a median Franklin listing price of $875,000 and a countywide median exceeding $1.3 million making affordability the central challenge.
Read Full ArticleThe Williamson County Board of Commissioners unanimously approved a resolution directing the County Mayor to solicit proposals for a study examining whether increasing the commercial rate of the Adequate Facilities Tax would require crediting back revenue collected under the Education Impact Fee — a legal balancing requirement that could reshape the county's entire development fee structure going forward.
Read Full ResolutionAfter a more than two-year legal battle, the Tennessee Court of Appeals affirmed that Williamson County has the authority to collect its Education Impact Fee from residential developers. The ruling, which followed an initial 2019 Chancery Court victory for the county, settled a challenge from the Home Builders Association of Middle Tennessee and cleared the county to collect more than $8.8 million in fees that had accumulated during the litigation.
Read Full ArticleIncorporated municipalities within Williamson County — each with its own development review authority and, in some cases, additional fee ordinances.
Compare development fees side by side across all six Williamson County cities — Brentwood, Fairview, Franklin, Nolensville, Spring Hill, and Thompson's Station. The interactive table breaks down every city-level and county-level fee by line item, with a home size slider that recalculates all amounts in real time. Fees shown include road impact fees, parkland fees, fire fees, facilities taxes, building permits, the Williamson County Privilege Tax, and the tiered Education Impact Fee.
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