Schöck makes thermally efficient balcony retrofit a reality

by Laura

The retrofitting of balconies, or the replacement of thermally inefficient balconies, on old housing stock renovation and projects involving office-to-residential conversion is in demand.  The challenge for planners though, is to comply with the same standards of thermal insulation as with new build. One of the most effective dedicated solutions on the market is the Isokorb from Schöck. It has a 120mm insulation thickness and is a load-bearing thermal break that allows the replacement, or addition, of balconies to an existing building by connecting cantilevered steel balconies to the reinforced concrete slab. The Isokorb minimises thermal bridges at concrete-to-steel cantilever balcony connections and transfers negative moments and positive shear forces. Standard heights of 160mm to 220mm are available and the product offers different options for integrated, energy-efficient building renovation, resulting in enormous scope for design. It is a ready-to-install component which allows residents to remain in the building during external renovation, with no damage risk to internal finishes and decoration. An additional feature is that the product has been fully certified as an “Energy saving component” by the Passivhaus Institute in Darmstadt, Germany

Installation utilses a template

Drill holes are first marked with a template in position on the face of the building.   Holes are then drilled into the concrete slab, adhesive injected and the load-bearing reinforcing rods slipped into position and anchored by means of the pre-injected adhesive. Structural screed is poured into a special pocket between the Isokorb and the concrete slab to ensure a perfect contact between the two structural elements. Once both the mortar and the screed are cured the structure is ready for the new balcony to be connected

The Schöck design team is on hand

Unlike new build, product selection for renovation is subject to certain restrictions.  The solution will depend on the specific project requirements, the existing building and its structure, as well as the development of customised design proposals.   The Schöck design team is on hand to provide extensive technical support on all these issues; for architects, developers, support structure specialists and contractors.   This includes product selection advice for the different options; building physics detail; framework conditions; methods for undertaking a building inventory; dimensioning examples and a comprehensive checklist.

All solutions meet full compliance with the relevant UK building regulations and offer BBA Certification and LABC Registration. When the Isokorb products are 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.   The range also complies with the Government Standard Assessment Procedure, SAP 2012, concerning CO2 emissions from buildings and respectively heat losses through non-repeating thermal bridges.

For a free copy of the Schöck Thermal Bridging Guide and / or the Thermal Bridging Solutions brochure – contact the company on 01865 290 890 or visit

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