As part of Landsec’s commitment to sustainable design and innovation, the two commercial buildings are being designed using a combination of the partial reuse of the existing structure for one of the buildings and the use of a hybrid/Cross Laminated Timber (CLT) structure for the other. Through this approach, the carbon emissions associated with the redevelopment, from all aspects of development, will be significantly reduced compared to a traditional office site redevelopment in the City.
Cross Laminated Timber – CLT – is a key element to the fabric of both buildings. CLT is a structural, prefabricated panel used to form a wide range of structures. Layers of lumbar boards are stacked crosswise at 90-degree angles and glued into place, reducing the movement of the wood, and ensuring that CLT more than meets standards required by modern building materials. CLT use has a wide range of advantages, not least the potential for reducing the construction vehicle trips associated with the redevelopment.
As part of our work with Landsec, we undertook a detailed exercise analysing the difference in construction vehicle trips generated by this hybrid build versus traditional build methods. The scenarios considered the partial demolition and hybrid build proposal put forward by Landsec for the site alongside the full demolition with traditional build scenario that could otherwise have been the case.
In transport terms, the benefit of a hybrid build is seen in the significant reduction in construction trips required through the build process. The reduction in construction trips is the result of two main features of CLT material:
- CLT floorplates are lighter, meaning more plates can be carried per truck; 100m3 of CLT can be carried per truck, compared to 6m3 of concrete.
- No concrete or wet trade is required, entirely eliminating the main trip generator in traditional build methods.
