March 2010

EXTERNAL WALL INSULATION TICKS ALL THE BOXES

By Gillian Allder,

Executive Director, Insulated

Render and Cladding Association

The UK is serious about addressing the challenges we face in preventing runaway climate change by putting in place the necessary measures to create a sustainable low carbon economy in the timeframes required.

Environmental performance is a key corporate and political issue. As a result the Government has implemented an expanding range of environmental legislation to ensure that targets to reduce carbon emissions are met. Hence the environmental performance is – or should be – top of the Agenda for schools. Those with a poor environmental footprint will be penalised, whilst those with good performance will be rewarded. Schools must look at how efficiently they use the energy they purchase and consume.

The Low Carbon Transition Plan (July 2009) sets out how the Government hopes to cut greenhouse gas emissions by 34% by 2020 and by 80% within 40 years. In the meantime Building Regulations will be progressively tightened this year and again in 2013 and 2016, as the government moves towards zero carbon construction for houses by 2016 and for non-domestic buildings by 2019 – with earlier targets for schools and public buildings.

When it comes to creating energy efficient, low carbon emission buildings to meet new legislation – both for new build and refurbishment – external wall insulation ticks all the required boxes.

External wall insulation (ewi) is specified because it is the simple, speedy way to build. It is now commonly used with modern methods of construction – steel and timber frame – as well  as traditional block, to provide insulation to today’s and future increasingly more stringent standards.

It is chosen for its weatherproofing properties; to add colour and texture; and to contribute to the design. It creates curved surfaces for ultra modern buildings; and quoins and other features are provided to match adjoining Georgian buildings. An additional benefit, particularly relevant to educational buildings, is its acoustic properties. The process gives design freedom for new build and overcomes traditional restrictions. The flexibility of ewi has freed up designers to do things not possible before. Thus it has the ability to be all things to all buildings.

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 is the solution that puts insulation in the optimum place within a building; that allows both new and old buildings to operate effectively and sustainably; and that lends itself to exciting, imaginative and radical designs and solutions.

In contrast to many lower cost insulation measures, external wall insulation systems, using insulated renders, are strategically poised to contribute towards achieving government targets for carbon savings, energy (or cost) saving and sustainability. The process meets the insulation criteria required by the Code for Sustainable Buildings. External wall insulation systems using insulated render will undoubtedly be at the forefront if these challenges are to be met, both for new build and refurbishment/regeneration.

External wall insulation cost-effectively simplifies new build construction; satisfies demanding thermal insulation requirements without long-term risk; and resolves refurbishment problems, including condensation and damp problems.

Advances in technology and innovative design have opened up a diverse market for insulated renders – both with masonry, and timber and steel framed construction. Designers are now beginning to change the basic thinking with regard to insulation and following the European building methods, where the recognised place to put the insulation is on the outside. Solid block construction using insulated render has been the predominant form of construction in Europe for many years. It can be put up faster than traditional building, yet still retain the traditional external appearance.

Existing buildings can be given a practical new future. The process is in demand for remodelling older redundant buildings to meet current and future Building Regulations criteria. It is very cost effective in replacing old render and obviating re-pointing. Heating and air conditioning capacity needs of the building are then greatly reduced.

In this context the process works very well combined with renewables – such as wind turbines; solar photovoltaic (PV) systems; solar hot water systems; and air and ground source heat pumps, to achieve very low carbon emissions and efficient use of energy.

The government has set a target of getting 15% of energy (heat, transport and electricity) from renewable sources by 2020. In order to achieve this, 30% of electricity must come from renewable energy sources (a five-fold increase from today’s rate of 5%): 12% of heat must be generated by renewables, and 10% of transport energy must be from renewables. These targets will only begin to be met if buildings are effectively insulated with the latest ‘state of the art’ measures such as ewi to ensure the minimum energy waste.

Through achieving higher insulation values, external wall insulation, in both new build and regeneration/rebuild, is one of the key measures to maximise the impact of Building Regulations – now and in the future – 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.

Continuing legislation coming through is encouraging new thinking about existing properties, and a much more aggressive attitude in determining whether to demolish. The pace will quicken, in spite of the recession, because of the multitude of environmental initiatives flowing through from European and UK governments. These are firmly supported by growing concerns of climate change, but also because of energy security of supply issues and energy pricing concerns.

In order to meet the demanding new standards of construction to achieve tomorrow’s sustainable buildings, attention is focussing on the insulated render industry. This is because external wall insulation can achieve much higher wall insulation values than other insulation methods. Tired buildings can be brought up to modern day standards of thermal performance, weatherproofing and appearance. Property life is extended and values improved. Heating demand is sustainably reduced – and any replacement heating systems can be of smaller capacity.

For the refurbishment of schools there is vast scope for utilising the benefits of external wall insulation. For example, the Humanitarians Wing of Lampeter Comprehensive School, Peterwell Terrace, Lampeter, Ceredigion, Swansea, was recently refurbished using the Permarock mineral fibre external wall insulation system with a silicone finish.

The specification was the modernisation of an existing building to the standard of the new block being built alongside. A particular design feature was a build up of 5mm insulated render encapsulating columns separated by panels and windows. A brick slip (burnt red) plinth around the perimeter was fixed with 60mm EPS insulation with a waterproof adhesive. The system consisted of 75mm of mineral fibre insulation above the plinth. The insulation is a hydrophobic, high laminar and compressive strength fire resistant mineral wool board with a U-value of 0.35W/m2K. The system designer was PermaRock Products Ltd; and the installer, Joyner PA (Cymru) Ltd – the latter two INCA members.

The INCA Register of Systems, giving their different properties, Register of Installers, providing their background and experience, and information on insulated renders for new build and refurbishment is available from the Insulated

Render and Cladding Association at

P O Box 12, Haslemere, Surrey GU27 3AH

tel: 01428 654011; fax: 01428 651401;

e-mail: info@inca-ltd.org.uk; or www.inca-ltd.org.uk.