With reinforced concrete construction, minimising linear thermal bridges at the wall connection to the floor, or floor slab, has been a perennial problem for the building industry. However, Schöck has introduced a dedicated new solution – the Sconnex type W. It is a product that offers outstanding insulation performance, combined with an exceptional load-bearing capacity.
Around 40% of all thermal bridges in a building are caused by walls and supports, which in turn are responsible for about 10% of heating energy losses. Schöck, the market leaders in the development of structural thermal breaks for balconies and other cantilever constructions, has now also applied its Isokorb expertise to reinforced concrete wall and support. Thereby offering an application-friendly and high-quality solution that contributes to a permanently sustainable building concept. The first major project to incorporate the new product is the Aylesbury Estate regeneration in the London Borough of Southwark.
Extensive regeneration required
The Aylesbury Estate, completed in 1977, was planned to house over 10,000 residents, with a design embracing concepts of modernist urban planning. During the 1990s however, despite its ambitions, the estate was considered one of the most deprived areas in the country. With deteriorating buildings and disillusioned residents, the estate was in need of extensive regeneration and Southwark Council considered the possibility of refurbishment. However, in 2005, having assessed the overall cost and benefits, it was decided that the best option was to demolish the existing estate and build new, better quality, mixed tenure homes. Various remedial developments have taken place since, but more recently the regeneration has escalated and currently there is a phased demolition and redevelopment programme which will see the Aylesbury Estate transformed into one of the most significant urban renewal projects in London.
Aylesbury Square is at the heart
Due for completion in 2036, the overall masterplan envisages 3500 spacious new homes in a combination of terraced housing, a contemporary update of the London mansion block and a series of taller buildings. Improved open spaces will also be a major feature. Pivotal to the scheme is Aylesbury Square, which is one of the earliest sites to be delivered. It consists of two separate blocks, from four to fifteen storeys, situated around a new public square forming the civic heart of the Aylesbury Estate regeneration. The North Building will provide 122 new homes on the square and it will also incorporate a community facility, which includes a public library and commercial space at ground level. The second block, the South Building, accommodates a Health Centre, along with a state-of-the-art Primary Care GP medical centre and Community Health Care facility. There is also an Early Years Facility on the top floor.
A serious source of linear thermal bridges
The construction of the two blocks is of reinforced concrete and the wall connection, to the floor or floor slab, has traditionally been a serious source of linear thermal bridges. The result being not just serious energy loss, but also the high risk of condensation. This can easily lead to mould growth, resulting in possible structural damage and worse, posing a health risk to the occupants. There is a sustainability strategy in place for Aylesbury Square, which is to ‘create a place which meets or exceeds the highest quality standards for new development in London.’ This is to be achieved by delivering highly energy efficient buildings as part of a London Plan policy compliant strategy using the BREEAM Communities sustainability standard.
Sconnex is a unique Schöck solution
The new Sconnex type W thermally insulating connection for reinforced concrete walls is unique in its ability to help to meet these criteria. This new Schöck product minimises the thermal bridge between the exterior wall insulation and the insulation above the floor slab, increasing the energy efficiency of the entire building. Thermal losses are greatly reduced and the surface temperature in the room increases to considerably more than the critical dew point temperature. Heating costs are lower, a pleasant room climate is created and the linear thermal transmittance (Psi) of the connected reinforced concrete wall is reduced by up to 90 percent. The outstanding insulation performance is combined with an excellent load-bearing capacity, which transmits very high pressure, tensile and shear forces in the longitudinal and transverse direction. This is made possible by the use of a pressure buffer consisting of ultra-high performance fibre reinforced concrete, a material which achieves compressive strength levels in excess of 175 N/mm2, but with extremely good flexural strength as well. A further important benefit is the generally significant cost reduction involved when compared to installing insulation beneath the floor slab.
For further information on the new Sconnex type W product contact Schöck on 01865 290 890; or download the brochure at www.schoeck.com