Musannaf Ibn Abi Shayba 13:807

Abu Bakr narrated to us, he said: Hafs narrated to us, from al-Shaybani, from al-Sha’bi, regarding a man who buys a house and then builds upon it, and then the person with the right of pre-emption (shafi’) comes. He said: He takes it with its building, or he leaves it. And Hammad said: He tears down its building and takes it.