Schöck wrapped parapets solution for Grade 1 listed rebuild
November 2019

At the Regent’s Park end of London’s Portland Place, passers-by have been astonished to discover that the iconic Park Crescent West, a Grade 1 listed residential Regency terrace built by architect John Nash, is no more. However, all is not as it seems. The original Nash terrace, completed in 1821, was badly damaged during the Second World War and restored in the 1960s. The work though was considered flawed and not true to the original. As a result this is now a rare case where the demolition of the Grade I listed terrace ‘and its replacement with a more scholarly replica would preserve and enhance rather than obliterate its significance’. Offering 76 luxury apartments, with nine mews houses at the rear and renamed Regent’s Crescent, the project will see the terrace rebuilt with new brickwork and stucco to represent the original Nash design.

Avoidance of thermal bridging is critical

The construction comprises a reinforced concrete frame with concrete columns, horizontal flat slabs and a lightweight steel roof. The project is to a very high specification and great attention has been paid to avoiding the risk of thermal bridging problems. Prevention along the parapets is critical, because as with balconies, parapets can allow conductive materials to transfer energy through the thermal barrier. Often the method of insulating parapets and parapet walls is to wrap the perimeter with an insulation barrier. However, the Schöck Isokorb 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. The Isokorb solution does not require maintenance and there is no risk of expensive restoration due to waterproofing problems. It also allows greater freedom of design and there is no risk of any additional thermal bridging through balustrade fixings.

A load-bearing modular thermal insulation element from the Isokorb range is also utilised within the lightweight steel roof construction. This is for connecting cantilevered steel girders to steel structures. It can be used to minimise the risk of therrmal bridging in new construction or renovation projects involving penetrating support structures such as canopy roofs, frame system crossbars or balconies.

Totally verifiable performance

The Schöck product types used at Regent’s Crescent are for wrapped parapets and steel-to-steel connectivity, but the comprehensive Isokorb range also offers solutions for concrete-to-steel situations and concrete-to-concrete. The range complies with the Government Standard Assessment Procedure, SAP 2012, concerning CO2 emissions from buildings and respectively heat losses through non-repeating thermal bridges. 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.