We acted as Structural Engineers on the redevelopment and extension of the Sentinel Building for Ardstone Capital, which comprised the proposed extension and refurbishment of the 84,104 sq ft, 9-storey commercial office building in Glasgow City Centre.  The project began with an initial feasibility assessment as one of the key challenges was to develop proposal options that could be constructed incrementally; some of the building’s tenants continued to operate in the building during the construction and renovation period.

Our role continued throughout each stage of the project and we had to carry out different roles at different stages.  During the feasibility stage, a new panoramic steel framed extension to the roof was designed as an option, and the core lift shafts were reconfigured and extended to accommodate the additional floor plate and improve the vertical transportation logistics. Strengthening works were also needed to the existing structural columns to bear the extra load of this extension.

The existing steel frame was modelled in Revit by our team and this model was used by the design team as their base model throughout the design development and detailed design. Finalised alteration options included strengthening of columns on non-occupied floors in anticipation for an extension at some point in the future, new high-speed lifts and an increased reception area with a bespoke floating feature window seat supported from a newly installed cranked concrete slab.

During construction, we were appointed to complete the temporary works design required to accommodate the strip out of existing floor plates and basement alterations. This involved temporary propping of existing composite floor slabs adjacent to newly formed penetrations and support to a historic masonry retaining wall within the basement.

As an add on to the original design scope, we reviewed the ongoing works being carried out to replace the external stone cladding. The original cladding panels covering the whole building were found to be in poor condition, requiring complete replacement. We reviewed the relevant sub-contractor’s packages and worked closely with various stakeholders to develop a workable solution.  This extensive collaboration with the design team, contractor and subcontractor required meticulous attention to detail and we needed to ensure that any issues were both discovered and corrected.  The close working relationships we developed with the subcontractor design team and specialist supplier’s technical groups were particularly valuable in ensuring that the best solutions were delivered on time and innovative structural solutions were implemented.