Commission expands planning commission review: all new commercial uses to require site plan approval

Williamson County commissioners voted unanimously on June 9 to amend the county zoning ordinance so that all new uses in commercial zoning classifications require site-plan approval from the planning commission, regardless of building size (Resolution 6 25 2).

The change replaces a size-based threshold that had allowed staff to review and approve site plans for buildings below a square-foot threshold. Planning staff and the planning director told commissioners the amendment responds to recent development proposals in areas such as Triune where parcels approved for residential uses will later include commercial parcels. Commissioners had raised concerns about the impacts of small commercial buildings on roads, infrastructure and surrounding neighborhoods.

“ This amendment will require all new uses in the commercial zoning classification to require site plan approval by the planning commission regardless of the size of the building that comes in, whether it be 1 square foot or 10,000 square feet,” Planning Director Aaron Holmes said while explaining the change.

Commission discussion noted that jurisdictions vary in how they define thresholds; county staff said the prior cutoff of 5,000 square feet had been chosen when the ordinance was adopted and that no single statewide “best practice” mandates a particular threshold. Supporters said the change will allow elected planners to review potential infrastructure impacts earlier in the process. The regional planning commission’s recommendation was recorded as 9 in favor, 4 against, 0 abstentions.

The resolution passed on a 22‑0 vote. County staff said the amendment applies countywide, including inside and outside any municipal or development districts, and will require planning commission review whenever a new commercial use is proposed.