Semicircular balcony demands resolved by Schöck

All apartments at the Triptych Bankside development, next to the Thames in Southwark, benefit from spacious balconies, with an emphasis on the quality of the finishes. However, their highly unconventional and dramatic semicircular profiling meant Schöck had to demonstrate its design expertise in meeting the structural load-bearing thermal break requirements.

Triptych Bankside is at 185 Park Street, in Southwark. It comprises three elegant building forms within a landscaped park setting and is a close neighbour of the Tate Modern, the Millenium Bridge and the Globe Theatre. The mixed-use development provides two residential blocks – fifteen and nineteen storeys respectively – along with office accomodation and creative workspace in a ten storey building. There are also retail and cultural amenities at ground level. A subtle twisting form, combined with undulating curved terraces wrapping around the exterior, affords the buildings a considered architectual elegance

– but central to the residential buildings design is also its ability to be adaptive and maximise both amenity space and local views. The development has a commitment to the local community too and Triptych Bankside is facilitating the delivery of 57 new, purpose-built almshouses, to be operated by the United St Saviour’s Charity, which has been working in Southwark since 1541. In addition the design reinstates the lost historic street, Emerson Place, which creates new pedestrian connections through the site to the River Thames and which features a continuous flow of green spaces including a central public square.

Special demands need a special solution

The special demands of the Triptych Bankside semicircular balcony profiling required bespoke Isokorb T type SK units to be designed with specific postional load capacities, using built-in steel reinforcement. The T type SK is a complete system structural thermal break for minimising thermal bridges between cantilevered steel constructions on reinforced concrete components. Since it can be prefabricated to a large degree, installation time on the building site is reduced. Also, due to its superb loadbearing capacity, the engineering and structural design is ideal, even for heavy modern balconies. It is capable of absorbing large bending moments and shear forces; and is certified as a safe and verifiable solution through independent third party evaluations from the BBA and Oxford Brookes University. At present, no other UK product for concrete-to-steel applications meets these load-bearing requirements, or meets the current and future thermal performance required by building standards (Part L).

Minimising thermal bridging is critical

The entire project is built very much with sustainability in mind and minimising any risk of thermal bridging at the balcony detailing is critical for a number of reasons. Namely, local heat loss will result in more energy being required to maintain the internal temperature of the building. Also, low internal surface temperatures in the area of any thermal bridge can cause condensation and this in turn is likely to result in structural integrity problems. Mould growth too is a possible risk, which in a residential situation can cause asthma and allergies.

A dependable and fully compliant product range

The Schöck Isokorb range of structural thermal break solutions is the largest in Europe and in the UK helps projects meet full compliance with the necessary Building Regulations (and the impending Future Homes Standard criteria where relevant). In addition to the Isokorb type used on this project, there are also solutions for concrete-to-concrete, steel-to-steel, renovation projects, Passive House – and even a maintenance free alternative to wrapped parapets. All products have the security of independent BBA Certification, which provides NHBC approval. The temperature factor requirement (fRSI) used to indicate condensation risk, which must be equal to, or greater than 0.75 for residential buildings, is also easily met by incorporating the Isokorb.

Contact Schöck on 01865 290 890; or visit the website at www.schoeck.com for full details of the Isokorb range