(a) Subject to the application requirements of § 67-5-212, land, including buildings on the land, owned by a charitable institution and held for the purpose of constructing one (1) or more single family dwellings to be conveyed for use as the residence of a low-income household as defined in § 13-23-103, shall be exempt during the period of its ownership by the charitable institution until the date it is conveyed to the adult head of the low-income household, but not to exceed the periods established in subsections (b) and (c). The effective date of exemption shall be determined under § 67-5-212. If a dwelling is not constructed and conveyed as provided in this section within such periods, the property shall be encumbered by the full amount of taxes together with penalties and interest that would otherwise have been due.

Terms Used In Tennessee Code 67-5-221

(b) If the property purchased is a single lot on which only a single family home may be constructed, the property is exempt for a period not to exceed eighteen (18) months.
(c) If the property is planned for subdivision into multiple single family lots according to plans filed by the organization, the period of exemption shall be eighteen (18) months plus six (6) months for each additional lot planned beyond the first. If a lot is not developed as planned, a proportionate share of taxes that would have been due upon the lot, including delinquency penalties and interest, shall accrue from the date of acquisition of the property by the organization. Taxes shall accrue on individual lots within a multi-lot development at the time each lot is conveyed as provided in this section.
(d) This section shall be implemented in any county upon the adoption of a resolution by two-thirds (2/3) vote of the county legislative body.