House Bill 402 proposes amendments to the Tennessee Code Annotated regarding property tax exemptions for real property that provides tree canopy coverage. The bill introduces a new section that defines key terms such as "tree canopy," "implementing agency," and "tree dripline." It allows property owners to apply for a property tax exemption based on the portion of their property that provides tree canopy, as determined by the implementing agency, which may include the county planning commission or assessor of property. The implementing agency is responsible for assessing tree canopy coverage using reliable methods and must be selected by the county's chief administrative officer with the approval of the county governing body.

The bill outlines the application process for property owners seeking the exemption, including requirements for filing and the conditions under which the exemption can be granted or revoked. It specifies that the exemption is not transferable and must be recertified every seven years, with the possibility of extension if deemed reasonable by the implementing agency. Additionally, the bill stipulates that the tax exemption only applies if the county governing body elects to adopt its provisions by a two-thirds majority vote. The act will take effect upon becoming law.