Archetech Issue 43 2019 | Page 37

SCHÖCK ISOKORB FOR LARGEST UK PASSIVHAUS DEVELOPMENT Claimed to be the largest Passivhaus development to date in the UK and Camden Council’s largest community investment project, Agar Grove Estate, in North West London, is undergoing a six-phase major regeneration, due for completion in 2025. It will deliver 493 new high-quality homes for existing residents, with maisonettes and gardens at ground level and apartments with full-width balconies on the higher floors. The project is to Passivhaus standard, meeting demanding levels of sustainability and energy efficiency. So the insulation to the thermal envelope results in exceptional levels of airtightness. A critical requirement here being the avoidance of thermal bridging, a frequent cause of increased heat and energy loss, condensation and possibly mould growth. TOTALLY VERIFIABLE PERFORMANCE The Schöck product types used at Agar Grove are for concrete-to-concrete connectivity and for wrapped parapets. But the comprehensive Isokorb range also offers solutions for concrete-to-steel and steel-to-steel. When any Isokorb type is incorporated into residential buildings, the required fRsi value – the temperature factor used to indicate condensation risk that must be equal to or greater than 0.75 – is always comfortably met. Products meet full compliance with the relevant UK building regulations, have NHBC approval and offer LABC Registration. There is also the security of independent BBA Certification. 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. THERMAL RISK IS AT BALCONY AND PARAPET CONNECTIONS The risk of thermal bridging is primarily at connectivity points involving the balconies and parapets; and one of the most technically advanced countermeasures is the Isokorb range of structural thermal breaks from Schöck. For the balconies, the Isokorb type used transfers both negative moments and positive shear forces. It has been awarded the “low thermal bridge construction” certificate by the Passivhaus Institute in Darmstadt, verifying its suitability for Passivhaus construction. With parapets, the conventional insulation method is to wrap the perimeter of the wall with an insulation barrier – but with the Schöck Isokorb designed for parapets, there is no wrapping required It is more cost-effective and more thermally efficient than conventional wrapping and its 120mm insulation dramatically reduces heat loss. There is no risk of any additional thermal bridging through balustrade fixings – and other key benefits are durability and water impermeability. The Isokorb does not require maintenance and there is no risk of expensive restoration due to waterproofing problems.