[2007] EWCA Civ 30, 1 February 2007. The applicant tenant Sitkowski applied for permission to appeal against a decision in possession proceedings brought against him by the respondent landlords (Tan). Sitkowski had been granted a tenancy of the premises in 1970 by the local authority. He used the ground floor for his business and used the first floor as a residence with his family. In 1989, he ceased using the ground floor for his business. In 1990, Tan became Sitkowski's landlords and in 2003 served various notices to quit on him, at least one of which was effective to terminate his tenancy. The possession proceedings were determined against him, and although he refused permission to appeal the judge expressed concern over one issue. When he was granted his tenancy in 1970, it enjoyed the protection of the Landlord and Tenant Act 1954 Part II, since he occupied part of the premises for business purposes. From 1989, the 1954 Act no longer applied to the tenancy. Sitkowski contended that, since he no longer used part of the premises for business use, the Rent Act 1977 S24(3) no longer applied, so that he enjoyed the protection of the 1977 Act. He submitted that, by the time the notice to quit expired in 2004, he was a protected tenant, and therefore became a statutory tenant on the expiry of the notice to quit. Tan contended that there was authority binding on the court that, if a tenancy was granted for mixed business and residential use, and was accordingly subject to the 1954 Act, the tenant could not, simply by unilaterally ceasing the business use, arrogate to himself protection under the 1977 Act; in such a case, the tenancy in question was not to be treated as being one of "a separate dwelling" within the 1977 Act S1. Sitkowski argued in the alternative that, even if his tenancy could not be treated as a letting of "a separate dwelling" from or before 1989, it had become such a tenancy by the time the notice to quit expired, and accordingly he was nonetheless entitled to claim a statutory tenancy. "Held": permission to appeal was granted but the appeal was dismissed. Tan did not know of the cesser of business use and had always assumed the tenancy was within the 1954 Act. The judge had been right to conclude that the nature of the tenancy did not change, so as to bring it within the 1977 Act.