Custom House is a major regeneration scheme in Newham, East London. A project which Schöck has been heavily involved in from the outset; initially providing full design support and installation training. The project is designed to Passivhaus standard, so the need to effectively eliminate any risk of thermal bridging at various points of the design detailing was crucial. As Europe’s leading supplier of innovative load-bearing insulation products, this is where Schöck really came into its own – with high performance solutions for the columns, balconies and parapets.

Known as the Custom House kickstart project and designed by Adam Khan Architects and Haworth Tompkins (for which they received a Housing Design Award) it is part of a wider masterplan by Adam Khan Architects. The main delivery partner is The Hill Group and the scheme overall consists of three mansion blocks, ranging in height from four to eight storeys. This first stage though will deliver 95 affordable homes, along with commercial space, community growing space, communal gardens and a high-quality accessible public realm.

The columns presented a special challenge

It is estimated that around 40% of all structural thermal bridges in buildings are caused by walls and columns; and these are calculated to be responsible for at least 10% of the heating energy loss. The recently introduced Schöck Sconnex range is a unique solution to this problem, allowing walls and columns to be directly and permanently insulated. There are three product variations, the type W, type P and type M. Specifically, the Sconnex type P is the product used at Custom House. It consists of a thermal insulation element and a reinforcement element, both of which are required to withstand the bearing load. The thermal insulation element has a pressure-resistant support structure, made of lightweight concrete and polypropylene fibres, all in a 100mm thick insulation layer. Its performance significantly reduces heat flow, but importantly, also eliminates the need the for the traditional solution of using cumbersome flanking insulation. On this occasion though, quite apart from effectively isolating the rectangular columns from the rest of the building, there were challengingly high load requirements. To meet these demanding loads, it was necessary to incorporate multiple Sconnex type P units at the head of each column – the first time this particular design solution has been used in a UK project.

Parapets are as prone to thermal bridging problems as balconies

Preventing thermal bridging at the Custom House parapets was also a critical consideration for such a high performance development, because as with balconies, parapets can allow conductive materials to transfer energy through the thermal barrier. Conventionally, in the majority of cases, the method of insulating parapets and parapet walls is to wrap the perimeter of the wall with an insulation barrier. However, the Schöck Isokorb XT type A used here offers a solution that is both more cost-effective and more thermally efficient than conventional wrapped parapets. Its 120mm insulation thickness results in low psi-values and therefore significantly reduces heat loss – and there is no wrapping required. An added benefit being there is no risk of any additional thermal bridging through balustrade fixings. Other key factors are durability – and significantly water impermeability – so there is no risk of expensive maintenance or restoration due to waterproofing problems.

High performance solution for the concrete balconies

For the concrete balconies at Custom House the tried-and-tested Schöck Isokorb XT Type K has been incorporated to meet Passivhaus standards. The XT type K with compression module HTE-Compact and 120 mm insulation thickness, is a load bearing thermal break element for free cantilevered balconies. It is the company’s most efficient thermal break ever, offering 30% more thermal performance than the standard Schöck Isokorb T type K.

The widest range in Europe

All of the Schöck products used at Custom House (the Sconnex type P, the XT type A and the XT type K) are certified by the Passive House Institute in Germany. With the Sconnex type P being the only column connection certified by the Institute. The fully compliant Schöck Isokorb range, whether for Passivhaus or standard solutions, offers the widest selection of structural thermal break solutions from any European supplier. In the UK, the range enables projects to meet full compliance with the necessary Building Regulations (and the impending Future Homes Standard criteria where relevant). There is also the security of independent BBA Certification, which provides NHBC approval.

Contact Schöck on 01865 290 890; or for full details of the entire product range visit the solutions page on the website at www.schoeck.com/en-gb/solutions-uk