The niu hotel Frankfurt/MArchitekthaber turri architekten Frankfurt/MFassadeSTP-DF-14/3B-WS STP-DF-14/3B-WS STP-DF-14/3B-WS STP-DF-14/3B-WS STP-DF-14/3B-WS STP-DF-14/3B-WS