Paragraph 5

Where part only of a hereditament is used for purposes other than those of a private dwelling or private dwellings and, if that part were a separate hereditament in the same occupation as the remainder of the hereditament and used solely for those other purposes, that separate hereditament would not be liable to be rated, the first-mentioned hereditament shall be deemed to be used wholly for the purposes of a private dwelling or private dwellings.