Responsa על בבא מציעא 165:1

Q. A demands from B rent for fifteen years, during which period B lived in his house. B claims that he paid the rent, and, in turn, demands payment for putting up, in A's house, certain necessary structures. A, however, claims that he did not ask B to put up such structures.
A. B should take an oath that he paid A the rent, and be free from that obligation. If B can prove, or if A admits, that he, B, put up the structures mentioned, B has a right to remove them.
SOURCES: Pr. 962.