Building Retrofit to Improve Energy Performance from Office to Accommodation. Case study: Tower Building, Nottingham, UKNissa Aulia Ardiani, Suhendri, Mochamad Donny Koerniawan and Rachmawan BudiartoMATEC Web Conf., 206 (2018) 02010DOI: https://doi.org/10.1051/matecconf/201820602010