The client's flat is located within a Victorian pump house building that has been converted into luxury residential spaces. Their requirement was for a new mezzanine structure to be installed within their existing, very tall, living room space. We worked with the interior designer to on a structure that would require no over cladding and give character to the space. The adopted solution uses a repeated cast iron plate for both the floors and the balustrades that acts as a torsional plate. The ribs in the plates are provided for strength in locations of maximum bending stress.