Portlands Place (N06 East Village)

90% reduction in defects through detailed off-site design with just mm tolerances

The N06 project follows on from sister project N08 in the East Village. Walsh was engaged directly with the developer to work up a new planning application for N06.

Key challenges were the coordination of the core designs, structural performance and design of the Skybridge. The Skybridge is a steel warren truss design of 6m-width and height with a span of 26m. The bridge frame is clad in glass as the bridge forms a key amenity space in itself.

Walsh contributed engineering excellence which allowed each floor to be built using off-site / MMC techniques. The innovative designs had a tolerance of just millimetres to achieve a greater degree of prefabrication than ever with cladding attached to perimeter panels off-site.

The towers were originally planned as a traditional in-situ concrete frame build and were converted by Walsh into what is in practice a precast concrete frame solution, a solution which had not been attempted before in the UK.

Each floor was divided into reinforced precast concrete units. This meant that the structure, cladding, pods, service risers, stairs, corridor, ceiling services and other fit-out items could be manufactured off-site and each floor erected in under three days. This was only possible due to the exceptionally detailed and accurate designs which incorporated tracking codes linking each manufactured unit to a just-in-time delivery system supported by Bluetooth transmitters.

The approach taken to off-site manufacturing by Walsh and MACE, delivered not only a 25% reduction in programme, but also reduced the embodied energy of the development by 15% through 75% waste reduction, 60% less on-site personnel and 40% fewer deliveries. The other remarkable result was a reduction in defects of 90%. This all resulted in significant time and cost savings for the client.