Kestrel explains why amidst all the hype about environmentally friendly windows, it's important to remember the role that next generation PVC-UE roofline products can play too.
Design & Sustainability Considerations Of PVC-UE Building Products
Environmental impact is more than just a matter of conscience in today’s building industry - it is a critical business driver. Sustainability, whether in building design, the carbon footprint of materials or in the actual building process itself, is under intense scrutiny and increasingly, regulation. Every stage of the supply chain has a part to play - whether you are an architect specifying roofline products, an installer choosing between timber or PVC-UE, a paint manufacturer reducing lead content or, like us, a manufacturer of PVC-UE products.
PVC Has A Place In Sustainable Building – Even According To Leading Environmentalists
In an interview last year, co-founder of Greenpeace Dr. Patrick Moore provided his views on sustainable building: “Guys! It’s not within our jurisdiction to eliminate an element of the periodic table!” Highlighting PVC as maligned materials in the green building industry, Dr Moore provided challenging perspectives emphasising the need for LCA (life cycle assessment) studies to identify true impacts. “There is absolutely no evidence that vinyl damages human health or the environment”, said Dr Moore. “Further, PVC is durable, low maintenance, recyclable and performs well on LCA tests.” In summary, PVC-UE is a material whose environmental benefits are all too often underestimated, especially the raft of next generation products currently being developed.
The Story Of PVC
Since pre-historic times, man has exploited for his own use the properties of natural polymers such as horn, waxes and bitumens. Over the years, it was gradually learned that the properties of such materials could be improved by techniques such as purification and modification with other substances. By the turn of the 19th century, the explosion of scientific knowledge in fields such as chemistry and physics, coupled with demands from industry for materials with properties not found naturally, created the environment for the development of a whole range of new materials - among them the early plastics. PVC was first introduced nearly 50 years ago as a building material. It is now the most widely used polymer in building and construction applications and over 50 per cent of Western Europe’s annual PVC production is used in this sector. In terms of source materials, PVC-UE is derived 57% from abundantly available common salt and 43% from oil. Only around 4% of the world’s oil production finds its way into the manufacture of all plastics, so the proportion attributable to PVC-UE is small.
PVC makes a major contribution to the quality, safety and cost-effectiveness of construction materials, as well as contributing to lower environmental impact of completed projects. In lifecycle analyses and independent studies, PVC’s environmental impact has been found to be favourable when compared with other manufactured materials used for construction. It is comparatively low in its energy and resource use during production, as well as in conversion to finished products. As a thermoplastic, PVC can be recycled and according to Recovinyl and Vinyl 2010, the ten-year Voluntary Commitment of the PVC industry to sustainable development, volumes being recycled continue to grow.
Myths & Home Truths
Over the years I have come across many myths about cellular foam building products, with one key objection resurfacing time again: the fact that it’s not as sustainable as competing materials. The fact is all materials have ‘issues’ when it comes to sustainability. The main alternative to PVC-UE in the building sector is timber, especially softwood. Both materials have similar workability, versatility and finished appearance. In recent years, treated timber has become a more expensive material than PVC-UE and from an environmental perspective, because timber distribution channels are longer and more fragmented, traceability is often not possible. Of course, the other environmental benefit of PVC-UE is that it’s a finished product with no need for surface coatings like preservatives, stains or paints. Not only are some of these treatments toxic, but they are required on regular repeat cycles which adds significantly to the whole life costing. In fact, it’s when you look at the question of the whole life costs of buildings, material lifecycles and the maintenance required, that the real benefits of PVC-UE can be appreciated. A building material’s lifecycle is also one of the few aspects of sustainability where it is possible to put a simple quantifiable factor into the arguments. This is because the number of times that a material needs replacing in a building’s lifetime multiplies up the whole life cost of that material. What may be a small difference in cost during the material’s lifetime can assume much greater significance over the building’s lifetime. PVC-UE performs well.
If PVC-UE is disposed of by incineration - preferably with heat recovery or as part of combined heat and power schemes, it has a similar calorific output as timber or paper, but produces less CO2 per kg of material than timber or coal. Extensive studies around the world have also confirmed that the chlorine present in PVC-UE has no more effect on Hydrogen Chloride or dioxin emissions than the very many other chlorine containing materials in incinerated household waste. Landfill studies by the Swedish Environmental Protection Agency, and the universities of Gothenburg and Linkoping, have also shown that PVC is effectively inert, with no significant risk. Disposal of materials that have been treated with preservative chemicals or exterior paint coatings requires care and is increasingly questioned. In fact, as PVC has been on the market for only 50 years, with its 35 year plus lifecycle only a limited amount of material is actually available for recycling.
Calcium To The Core
Eliminating the lead content in PVC-UE has been a matter of particular concern for responsible manufacturers in our industry. As recommended by the European Commission, UK Government and the PVC industry’s Vinyl 2010, now Vinyl Plus initiative, some suppliers have already made the switch. Kestrel is among those leading the way. In fact, we believe we are ahead as the only supplier in the UK to offer calcium core and skin in our PVC-UE. As well as future proofing the product for our customers in case new legislation on material usage does come into play, we are also doing what we can now in the global drive for environmental protection.
The Marketing & Use Directive 76/769 EEC
Under this directive, DiButyl Tin (DBT) stabilisers of the type used by a number of PVC-UE profile manufacturers will be banned in articles for supply to the general public containing greater than 0.1% by weight of tin by January 1st 2012, or by derogation in some applications by January 1st 2015. In practice it is by no means clear if all roofline, cladding and window trim products fit in the former or the latter of these bans. For example, product used as a window board would appear to be banned by January 1st 2012, whereas the same product used as a replacement fascia may be subject to the derogation.
DiOctyl Tin (DOT) stabilisers of the type some producers claim to be using to replace DBT, at least in the cellular core, are also subject to restrictions under Directive 76/769 EEC. After 1st January 2012, these too will be banned from certain products that come into contact with skin, including childcare articles and wall coverings and this could include cladding. Calcium organic stabilisers are not subject to any restrictions under Directive 76/769 EEC.
BRE Award PVC-UE Cladding An A+
The 2008 Green Guide to Specification from the BRE (Building Research Establishment) recognised the sustainable benefits of PVC by awarding PVC-UE cladding and its installed components an A+ rating – the highest possible for any material. This independent assessment endorses the PVC-U building material industry’s long running campaign that our products help specifiers achieve the highest levels under the Code for Sustainable Homes.
The guide evaluates the performance of materials and building materials in all the main building elements against 13 specific environmental impacts including climate change, human toxicity, ecotoxicity, waste disposal and fossil fuel depletion. Performance is then ranked on an A+ to E scale, helping specifiers select building elements which minimise environmental impacts. As the market leader in the manufacture of PVC-UE building materials, Kestrel is delighted that the critical role our products can play in the drive for sustainability and reduced carbon emissions has finally been officially recognised.