Building Act Article 11

The “building base” mentioned in this Code refers to ground occupied by a building and the statutory vacant space preserved. Where the building base is in several lots, application shall be submitted to apply for merging them into a whole one.The above-mentioned statutory vacant space of a building shall include the spaces between the building and the surrounding roads or other buildings, and the width will be prescribed in the building regulations.The statutory vacant space may not be divided, transferred, or designated repeatedly unless otherwise prescribed. The necessary conditions for division and the procedure for application shall be determined by the central competent authority of construction.
中文原文 建築法第11條
本法所稱建築基地,為供建築物本身所占之地面及其所應留設之法定空地。
建築基地原為數宗者,於申請建築前應合併為一宗。
前項法定空地之留設,應包括建築物與其前後左右之道路或其他建築物間之距離,其寬度於建築管理規則中定之。
應留設之法定空地,非依規定不得分割、移轉,並不得重複使用;其分割要件及申請核發程序等事項之辦法,由中央主管建築機關定之。

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