Covering the issue

Covering the issue

One way of achieving sustainability is by correctly insulating the exterior of the building. Kingspan reports on the innovations being made in this area.

The pressure on hospital development is mounting. It is fuelled not only by the requirement to achieve best value, but also by Government initiatives and European Directives aimed at providing sustainable outcomes. This means that whenever buildings are refurbished or newly constructed they need to have minimal impact on the environment, whilst meeting current Building Regulations. Not only this, the requirement to wherever possible meet the challenging criteria of cost effectiveness and low maintenance also have to be considered. While it is feasible to achieve this, there is a product that can take sustainability one step further by not only improving the working environment but actually reducing the running costs of a building, saving more over its lifetime than the initial cost of installing it. That product is insulation. To gain a true understanding of the benefits of insulation it is useful to look at the increasingly popular concept of whole life costing, which places a new emphasis on the long term cost involved in constructing and running a building. Whole Life Costing is defined in the emerging ISP Standard 15686 on Service Life Planning as “a technique which enables comparative cost assessments to be made over a specific period of time, taking into account all relevant economic factors both in terms of initial capital costs and future operational costs” – a definition that works equally well for the construction industry. CRISP, (the Construction Research and Innovation Panel) calls it “the systematic consideration of all relevant costs and revenues associated with the acquisition and ownership of an asset.”

This holistic approach looks at the whole range of expenses incurred, including the cost of staffing. As an example, The Royal Academy of Engineering has expressed in ratios the whole life operating and owning costs of an office, over a period of 30 years. Construction would account for one part, operational costs would take five, and staffing a staggering 200 parts of the whole. This demonstrates that savings made in the capital outlay for construction are insignificant compared to the overall running costs of the building, and that therefore it is more important to focus on a construction that promotes low maintenance, operational efficiency and minimises energy consumption. By choosing the right insulation materials for walls, roofs and floors, much can be done towards this goal without significantly increasing the capital outlay, whilst simultaneously achieving compliance with the requirements of Approved Document L2 at the same time. However, Approved Document L2 is not the panacea. Proponents of sustainable building design argue that U-values should be made as low as possible as reducing heat loss is the key to building sustainably. But what are the best materials for this type of construction? The two main attributes when selecting insulating materials are of course thermal effectiveness and longevity of performance. For “thermal effectiveness”, read “space.” To achieve an enhanced (more sustainable than Approved Document L2) U-value of 0.25 W/m2.K, using a traditional insulation such as mineral fibre, would require an insulation thickness of around 140 mm in a standard masonry cavity wall. Modern insulants such as rigid phenolic and urethane boards, being thermally more effective, would require a thickness in the region of 75 mm. These high performance insulants offer increased habitable space by reducing the overall required thickness of the construction elements.

However, the sustainability of a building does not end with construction, it has to go on for the life of the building. The design U-value must therefore be long term. The performance of traditional materials may deteriorate with any increase in moisture content, and with air infiltration. In some cases heat loss can be increased by up to 100% or more. Zero ODP rigid phenolic and urethane insulation boards on the other hand are unaffected by air movement and are resistant to the passage of water vapour, so they also offer excellent long-term performance and clearly could be regarded as the most sustainable insulation option.

Whole life costings can play a particularly important role where developments are funded through PFI. A massive L4.2bn is projected to be invested in the NHS by 2008 through this means, and a primary requirement will be that buildings must be cost-effective and provide value for money. By investing in high quality, highly effective insulants, energy costs can be significantly reduced. Improved insulation was a factor in the success of Withybush Hospital in Pembrokeshire, which reduced its total energy cost from the typical value of L6.60 per square metre to just L3.94 per square metre.

For those investing in the buildings and paying for the running costs and maintenance, the benefits are obvious – sustainable construction and reduced bills, profit and the environment for once in harmony instead of adversely affecting each other. High performing insulation will also contribute greatly towards the achievement of the target set by the NHS for a 15% reduction in annual primary energy use by 2010. The same argument can be used with long-term energy use as with cost. It is typical that one of the elements that comes under examination in the course of an analysis of the sustainability of a building is its embodied energy. Insulation for Sustainability, a study by engineering and design consultants XCO2 conisbee, who have done groundbreaking work and research around sustainability in the built environment, demonstrates that for insulation it is crucial to look at energy in-use rather than simply reacting simply to embodied energy. The study also demonstrates that specification decisions should not be made on the grounds of reducing embodied energy if, as a result, they put at risk “in use” energy performance at risk.

Kingspan Insulation produces a wide range of phenolic and urethane insulation solutions for floor, roof, wall and ducting applications. When properly applied the products have an unlimited life, they are lightweight and easy to install, and are extremely thermally efficient, achieving or exceeding required U-values with minimal thickness. There are products suitable for new build and refurbishment projects, making sustainability a reality, and reducing the pressure on limited resources.

Copyright Wilmington Publishing Ltd. Jul/Aug 2003

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