Knauf Insulation has supplied its Earthwool® RainScreen Slab to a sophisticated new façade system installed on Alumet’s headquarters in Southam, Warwickshire, to ensure optimal fire, thermal and acoustic performance. The key to Knauf Insulation securing the project was its ability to provide in depth technical support, including complex heat flow modelling calculations, which were carried out in accordance with the guidelines set by the BRE.
As part of a full exterior refurbishment, building envelope contractor, Alumet, required a new façade system that would transform and modernise the exterior of the Jubilee House building, which was originally installed in the early 1970s. Coupled with this was the requirement to improve thermal and energy efficiencies. The brand new Schueco ERC 50 Renovation Façade system, manufactured from 100 per cent recyclable aluminium - the first of its kind in the UK - presented a viable solution, providing the building envelope with high levels of insulation and triple glazed windows, as well as Building Integrated Photovoltaics.
Integral to choosing the type of insulation was Knauf Insulation’s Technical Advice and Support Centre, which provided 3D numerically modelled U-value calculations in line with BS EN ISO 10211 - thereby ensuring the thermal performance of the façade system was calculated taking into account the specific system brackets, which act as a significant cold bridge within rainscreen cladding systems.
For this project, Knauf Insulation’s Earthwool RainScreen Slab was installed on the brick facade of the existing building, which once complete, significantly improved the U-value thus reducing the heat loss through the wall
The insulation layer is a fundamental component of any successful rainscreen cladding system and mineral wool insulation delivers a number of advantages for this type of application. Earthwool RainScreen Slab is a rock mineral wool slab containing a water repellent additive, designed for use on masonry wall constructions and as the outer insulation layer in steel frame projects.
Quick and easy to install, the product is simple to cut and fit around brackets. The slabs then knit together to create a snug fit, with no need to tape the joints as may be required with rigid foam boards – ensuring maximum acoustic and thermal performance.
Fire and acoustic performance are key considerations when specifying insulation for a façade system. Approved Document B states that external insulation in any building of 18 metres or more (approximately seven storeys) should be of limited combustibility. Built over two storeys, the new Alumet building does not fall within this requirement but the designers were keen to capitalise on the acoustic benefits and improved fire protection the system would bring. Knauf Insulation’s Earthwool RainScreen Slab is non-combustible and has the highest Euroclass A1 reaction to fire rating, as well as having excellent sound absorption performance.
Alumet is expecting tangible financial benefits from its investment, which include lower energy costs due to the high levels of insulation in the façade that will reduce the need for heating in the winter and air-conditioning in the summer. Along with the Feed in Tariff payments from the solar panels, the indoor environment has been vastly improved and the exterior reflects the smart, modern image of the company.
Alumet Director, Dean Walton comments: "We wanted to turn our headquarters into a living testament to renewable technologies and to really project a modern ‘green’ image. The Schueco Façade system, along with Knauf Insulation’s products, helped us to achieve this as well as dramatically reducing our carbon output.
“The installation of the new system was seamless and our staff were able to remain uninterrupted during the whole operation. We have received some fantastic feedback from local residents saying how good the new façade looks and coupled with the improved thermal efficiencies, we are very pleased."
Mike Lane, Managing Director of Schueco UK explains: "With the requirement for highly insulated building fabrics, the ERC 50 Renovation Façade system complete with Knauf Insulation’s Earthwool RainScreen Slab, provides the perfect solution; delivering fast and stylish building renovation without loss of income for the building owner or disruption to the occupiers. Also, when it is fitted with PV modules, the system becomes a generator of energy."