(a) Power to grant exemptions.--Each local taxing authority may, by ordinance or resolution, exempt from real property taxation the assessed valuation of improvements to unimproved residential property in the amounts and in accordance with the provisions and limitations set forth in this act. Prior to the adoption of the ordinance or resolution authorizing the granting of tax exemptions, the local taxing authority by ordinance or resolution shall affix the boundaries of the unimproved residential property or properties wholly or partially located within its jurisdiction for which the tax exemption shall be available. Such ordinance or resolution shall also specify the purpose for determining such boundaries, including, but not limited to, maintenance of neighborhoods, consistency of zoning districts, rejuvenation of blighted areas and development of vacant property. Prior to the adoption of the ordinance or resolution authorizing the granting of tax exemptions, the local taxing authority shall conduct at least one public hearing for the purpose of discussion of the provisions of the ordinance, including, but not limited to, the abatement period and the exemption schedule. At the public hearing, local taxing authorities, planning commissioners, redevelopment authorities, and other public and private agencies, individuals, associations and corporations which are knowledgeable and interested in the improvement of unimproved residential property may present their recommendations concerning the location of boundaries of the unimproved residential property or properties for the guidance of the local taxing authority. The ordinance or resolution adopted by a local taxing authority shall specify the cost of improvements per dwelling unit to be exempted, and the schedule of taxes exempted.

(b) Cooperation between municipalities.--Two or more local taxing authorities may join together for the purpose of implementing this act. The local taxing authorities may, by implementing ordinance or resolution, agree to adopt tax exemptions contingent upon the similar adoption by an adjacent local taxing authority or by a local taxing authority with mutual jurisdiction, within the limitations provided herein.

(c) Limitation.--In the event a local taxing authority enacts an ordinance under subsection (a) and subsequently amends the ordinance to shorten the abatement period provided for in the original or latest version of the ordinance, the taxing authority shall not reduce the abatement period for those property owners eligible for and participating in the previously enacted abatement program. In the event a local taxing authority enacts an abatement ordinance under subsection (a) and subsequently amends the ordinance to extend the abatement period provided for in the original or latest version of the ordinance, the taxing authority may extend the abatement period for those property owners eligible for and participating in the previously enacted abatement program provided, however, that in no case shall the original period plus the extension result in an abatement period that exceeds two years.