|(a) A permit or permit amendment under this chapter is void if the permit holder does one of the following: (1) fails to begin construction within 18 months of issuance, except as noted in subsection (b) of this section; (2) discontinues construction for more than 18 consecutive months prior to completion; or (3) fails to complete construction within a reasonable time. (b) The executive director may grant extensions to begin construction. Permits issued to holders who have received extensions will be subject to revision based on best available control technology, lowest achievable emission rate, and netting or offsets as applicable. A first extension of 18 months may be granted solely at the request of the permit holder. One additional extension of up to 18 months may be granted if the permit holder demonstrates that emissions from the facility will comply with all rules and regulations of the commission and the intent of the TCAA, including protection of the public's health and physical property; and (1) the permit holder is a party to litigation not of the permit holder's initiation regarding the issuance of the permit; or (2) the permit holder has spent, or committed to spend, at least 10% of the estimated total cost of the project up to a maximum of $5 million. (c) A permit holder granted an extension under subsection (b)(1) of this section may receive one subsequent extension if the permit holder meets the conditions of subsection (b)(2) of this section.