The Equalization of Land Rights Act Article 73

On lands purchased at their declared values and resold according to Articles 26, 72 and 76, and lands sold according to Subparagraph 5 of Paragraph 1 of Articles 55-2, the purchaser shall begin construction within one year from the date of purchase. In case no construction has begun within the set time limit, nor has a request for postponement of construction been made and approved, the said land may be taken at its original purchase price by the Special Municipal Government or the County / City Government.The period for the postponement of construction as referred to in the preceding Paragraph shall not exceed six months.
中文原文 平均地權條例第73條
依第二十六條、第七十二條、第七十六條照價收買後再出售之土地及依第五十五條之二第一項第五款出售之土地,其承購人應自承購之日起一年內興工建築;逾期不建築,亦未報准延期建築者,直轄市或縣(市)政府得照原價收回。
前項延期建築之期限,不得逾六個月。

English translation for reference only; the Chinese text prevails. Not legal advice.