Issue D/J 06/07
Insulated render and cladding leads the field in energy efficient building design
Acontributory factor to global warming is energy waste in buildings which is running at a phenomenal rate and in addition the continual rising cost of energy poses an equally serious threat.
Modern methods of construction now need to be adopted by all builders and developers if they are to keep up with regularly increasing thermal insulation standards within Building Regulations (Part L) and the Energy Performance of Buildings Directive (EPBD) introduced this year. In order to meet the necessary criteria, it is now evident that external wall insulation reflects the latest trends in building design and is now recognised as a cost effective modern method of construction.
The measures set out in this new legislation will make a major contribution to the UK Climate Change commitment. The legislation aims to promote the improvement of buildings’ energy performance and reduce carbon dioxide emissions. In order to comply with these carbon saving targets, insulation values have substantially increased. Through achieving higher insulation values, external wall insulation – in both newbuild and regeneration/re-build fields – is one of the key measures to maximise the impact of Building Regulations on climate change. The process will improve the U-value of walls to 0.27W/m2K with ease, with values down to as low as 0.2W/m2K or lower without difficulty.
Several of the new requirements for improving thermal insulation focus attention on the advantages of placing the insulation as near as possible to the external surface of the building, whether new build or retrofit. The now pressing need for sustainability of buildings as well as other resources is creating a new demand for solutions to reducing wastage and pollution. Insulated render and insulated cladding is the solution that puts the insulation in the optimum place within the building; that allows both old and new buildings to operate effectively and sustainably; and that lends itself to exciting, imaginative and radical designs and solutions for all types and conditions of buildings.
The versatility and flexibility of insulated render and cladding systems, which reflect the latest trends in building design and aesthetics, enables the process to be applied to every type of building.
The external wall insulation industry is justifiably proud of the wide range of prestigious and worthwhile projects it is now undertaking – all due to the flexibility of the process. The industry has always adapted to its changing market – initially a basic insulation and weather-proofing product to combat cold and damp in social housing; then exciting new textures, colours and finishes, such as brick effect renders or slip for interesting combinations and traditional housing; more recently flexible insulated render systems that provide seamless facades for towers, curved surfaces and other imaginative architectural design; and over the last couple of years systems that combine with modern methods of construction, particularly steel and timber frame.
With regard to framed construction, insulated render systems have been used successfully on a range of supporting materials in concrete and steel framed structures on commercial buildings, schools, hospitals and private and social housing. These buildings have been insured for up to 20 years and have an assessed life of at least 30 years.
The new publication ‘Insulated Render Systems Used with Light Steel Framing’ produced by the Steel Construction Institute, in conjunction with the Insulated Render and Cladding Association, gives design guidance to assist specifiers on insulated render and cladding systems as applied to light steel framing as the supporting wall structure.
The use of light steel framing is relatively new (the first projects date from the late 1980s) and experience of the use of insulated render and cladding on light steel framing has been good.
However, in view of some failures in North America of timber framed housing which appears to relate to the use of poor quality timber and poor workmanship, the UK industry felt an authoritative guide to be essential. INCA was determined that the North American experience would not be repeated in the UK. It was therefore regarded as essential that specifiers, together with the industry itself, had a reference guide detailing best practice and how it could be achieved.
Light steel framing is used in housing, in infill walls in multi-storey buildings and in over-cladding in renovation. It is increasingly used to support lightweight cladding systems and achieves both constructional and performance benefits.
The use of insulated render and cladding has rapidly increased in the last five years to meet the demand for lightweight, energy efficient and architecturally interesting façades in residential buildings. It was therefore important to develop good practice details to assist specifiers, particularly addressing detailing and the avoidance of water penetration, which might affect the durability of supporting framework. Advice is given on choosing details appropriate to the degree of exposure to winddriven rain. A performance scoring system is presented and the minimum requirements are based on the BRE exposure classifications of sheltered, moderate, severe and very severe exposures.
It is suggested that for ‘sheltered’ or ‘moderate’ exposure, a cavity behind the insulated layer is not required, but a double barrier or cavity, or other back-up system is generally required for severe and very severe exposure conditions.
“This publication is the essential guide for professionals who aim to deliver best in class buildings,” says Mark Lawson SCI Professor of Construction Systems of the University of Surrey.
The publication not only provides design guidance, but it also demonstrates the benefits of insulated render and cladding in terms of thermal efficiency, acoustic performance and sustainability, while improving weatherproofing and aesthetic appearance.
The implementation of the New Part L, together with the growing concern for global warming and the need for more sustainable buildings, clearly establishes the new publication as a crucial tool that will empower specifiers who aim to design better and more efficient buildings.