Every owner of a party wall may use it in proportion to the right he may have in the part-ownership. He may, therefore, build, supporting his structure on the party wall, or introduce joists up to one-half its thickness, but without interfering with the common and respective uses of the other part-owners.\nIn order that the part-owner may make use of this right, he must previously obtain the consent of the other parties interested in the part-ownership; and should he not obtain it, the conditions necessary in order that the new work may not injure the right of the former shall be fixed by experts.\nHistory —Civil Code, 1930, § 515.
Puerto Rico Legal Code