The existing building was a dated office block requiring up-grading. The assessment of the existing structure and foundations confirmed the viability of in-filling a central light-well and adding two storeys of residential accommodation to be served by its own separate entrance. New cladding was provided to enhance the thermal performance and improve the appearance of the building.
A comprehensive intrusive structural survey was carried out to obtain information regarding the existing structure and detailed calculations were carried out to assess the capacity of the existing floors, walls and foundations. New columns on piled foundations were introduced to carry the light-well in-fill structure and some of the existing foundations were strengthened where they couldn’t be justified for the new loads.
In order to minimise the need for strengthening, the new roof-top extension was designed using lightweight materials. A steel frame located above existing columns and walls was adopted with timber floor and roof plates. The light-well infill was also steel framed with thin composite floor slabs to minimise weight and facilitate construction within the existing building.
