The opportunity

We manufactured a U-shaped steel framed structure for nine storeys plus the basement. It includes four new lecture theatres, eighteen classrooms, research facilities and offices.

The operation

Demolition work removed all existing floors while retaining the original façade. As each floor was demolished, we erected new permanent steelwork to support the retained grid bay.

Working behind a retained façade meant that all steel members had to be hoisted onto the site with a tower crane and all sections had to be kept to a minimal length and weight. The connections to the existing steelwork were very labour intensive as each of the old riveted section plates had to be welded together before being drilled.

To further increase the flexibility of floor area usage we removed four existing columns from each level and inserted transfer beams above these. Adjacent columns were also strengthened by the use of concrete encasements to support the extra loads.

The result

A key objective of the refurbishment was to create more open plan floors for the building. This was achieved by suspending the new floors from a roof level transfer truss, which enabled both the ground and lower ground floor to be free of internal columns.