SD Structures applied their experience in building appraisal to add 130 new units above an existing two storey commercial unit in the heart of Peterborough town centre.
The existing post war structure consists of internal steel framing and load bearing masonry to the perimeter, and has been heavily modified and extended over its life. A full historic desk study was undertaken in the local archives, and the findings were verified through extensive on site survey. These findings were then converted to a structural analysis and 3D draughting model.
Access to the ground floor was prohibited and no structure could pass through the existing first floor slab, meaning that existing foundations had to be utilised and balanced with historic values. In locations where load was increased, piles were tested and back analysed.
Converting a historic masonry structure from two to five stories required a novel hanging frame to be designed to support the external 8m wide perimeter bays in the event of a catastrophic explosion blowing out all of the perimeter walls. Section sizes were reduced through the specification of a two storey Vierendeel truss being constructed from the existing internal column bays.