Design Buy Build Issue 40 2019 | Page 35

Schöck shows its capability at major North London development The former site of the National Institute for Medical Research (NIMR), set high on The Ridgeway at Mill Hill, in North London, is being redeveloped as a major new Barratt London residential development known as Ridgeway Views. The main NIMR building, with its distinctive green copper-roof, has been a local landmark since the Institute first moved there in 1950. However, during the noughties the Medical Research Council decided the NIMR would need to relocate and in 2016 it became part of the Francis Crick Institute, based at a new building in St Pancras. Work on the forty-seven acre Ridgeway Views site began in 2018 and the full Barratt London scheme is due to be completed by the end of 2021. It is planned that there will be around 460 residential units, with apartments across nineteen buildings of three to nine-storeys and twelve three-storey houses. In addition, new offices, leisure facilities and a café with hilltop views will all feature. Thermal performance is critical Minimising energy use by improving thermal performance in the buildings across the development is key and the prevention of thermal bridging is critical to this. Particularly within the balcony and parapet detailing. Ineffective insulation at the connection points means local heat loss, resulting in more energy being required to maintain the internal temperature of the building. There are other potential issues too. Low internal surface temperatures around the thermal bridge can cause condensation, leading not only to structural integrity problems with absorbent materials such as insulation products or plasterboard, but the potentially serious occurrence of mould growth as well. Parapets are just as prone to thermal bridging problems as balconies. A variety of connections The comprehensive Schöck Isokorb structural thermal break range meets full compliance with the relevant UK building regulations, has NHBC approval and offers LABC Registration. To keep thermal bridging to a minimum, Schöck Isokorb structural thermal breaks are being installed throughout. For the concrete-to- concrete cantilever balconies it is mainly the Isokorb with 80mm insulation thickness that is used to transfer both negative moments and positive shear forces. For the recessed balconies where there is continuous support, a variant of the concrete-to-concrete unit is installed, transferring positive and negative shear forces Steel-to-steel connectivity detailing on the project uses a modular unit able to meet practically any profile size and load-bearing capacitiy. A special requirement involved a steel balcony needing to be bolted down to a precast plank. And to achieve this an L-shaped bracket was first fixed to the slab, then a stub bracket and balcony attached to the bracket using the modular Isokorb. The Isokorb with 120mm insulation thickness for parapets and balustrades is used within the first phase of the development. 35 The conventional insulation method is to wrap the perimeter of the wall with an insulation barrier – but with the Isokorb there is no wrapping required Totally verifiable performance There is also the security of independent BBA Certification. The requirement too that the temperature factor used to indicate condensation risk (fRSI) must be greater than, or equal to, 0.75 for residential buildings is easily met by incorporating the Isokorb. Contact Schöck on 01865 290 890; or visit the website at www.schoeck.co.uk for a free copy of the Schöck Thermal Bridging Guide; the Schöck Specifiers Guide and to view the full range of downloadable software.