Newington Butts - AKT II
Project Details
Project - Newington Butts
Sector - CLT
Technology -
Company - AKT II
Project Overview
The "Newington Butts" project began as a research-based proposition back in 2003 between Client Firstbase, Architects RSH+P and AKT II as Structural Engineers. The brief was simple: to create a new residential typology which was lean, flexible and driven by a standardised and prefabricated approach.
In terms of the tower, we wanted to take the onus away from the central core in terms of providing stability function, allowing the core design to be lean in terms of size and thickness of walls. Thus we needed to find a supplementary stability system which could be integrated into the required residential brief. To achieve this we researched using the an "outrigger system" to mobilise the full stiffness of the tower footprint, but instead of dedicated "outrigger" floors, all the RC flat slabs act as outrigger arms mobilising the perimeter structure. This outrigger system was made possible by utilising 8 perimeter wall panels and 4 internal "locking" wall panels, thus maximising floor plate flexibility. These 12 wall panels per floor are all standardised precast units (either twin wall or solid) and repeat up the tower meaning the design and construction benefited from the quality control and programme advantages of off-site manufacturing techniques.
The 8 corner balconies are also prefabricated and repeat up the tower. To achieve the required dynamic response, the balconies are linked together via tension rods to mobilise the global mass of the system in terms of dynamic damping.
The adjacent podium block was defined by a more linear system of loadbearing walls between units and thus the inherent efficiency and redundancy of timber CLT construction was utilised. All components of the primary frame were constructed from CLT including façade panels and lift cores, thus maximising the benefits of supply chain and knowledge.
Testament to the flexibility achieved through this early design logic was then when the client and architect changed in 2011 along with the market and tenure, the structural logic remained robust, and the inherent flexibility of the system meant that the floor plates could accommodate a change of mix and tenure. To continue to evolve this unique integrated design typology, we have installed anemometers and accelerometers at the top of the tower to measure the tower's dynamic behaviour, the results of which will feed back into our continuing research and design.
