Environmental proof your roof
Steve Bryceson, technical advisory service manager from Marley, discusses why embodied carbon, responsible sourcing, European Product Declarations and end of life recycling are set to become an increasingly important part of roofing specification for housing associations.
With housing the biggest single contributor to the UK’s CO2 emissions, social landlords are pivotal in the UK’s success in meeting its targets of an 80% reduction in carbon emissions by 2050.
While the A+ rating gives reassurance of a product’s sustainability, housing associations increasingly need to be able to prove not only the amount of energy that has been used throughout the life of a product but also that it has been responsibly sourced. This means that embodied carbon, responsible sourcing, Environmental Product Declarations and recyclability are becoming an important part of roofing specification for housing associations.
Already adopted in the UK, housing associations should look out for products that are certified to meet the requirements of the BRE standard BES 6001 ‘Framework Standard for the Responsible Sourcing of Construction Products’. This certification is awarded to manufacturers that can demonstrate responsible sourcing throughout the whole lifecycle of a product, from initial extraction of the raw materials through to manufacturing and processing, installation, use, re-use and recycling, until final replacement - as well as the environmental and social impacts of its procurement through all stages of the supply chain.
While there is actually no mandatory requirement for any products to be responsibly sourced at present, it does enable specifiers and users of BES 6001 accredited products to achieve the highest credits in The Code for Sustainable Homes and BREEAM certification schemes. Marley has achieved a ‘Very Good’ performance rating for its clay plain tiles under the standard, making us one of the first roofing product manufacturers to attain this accolade and demonstrating our commitment to leading the market in this arena.
Responsible sourcing will become increasingly significant as, through the ‘Strategy for Sustainable Construction’, there are already targets for 25% of all construction products to be responsibly sourced.
Embodied Carbon / Carbon Certification
Embodied carbon (CO2e) covers all greenhouse gas emissions that arise from the energy and industrial processes used in the processing, manufacture and delivery of the materials, products and components required to construct a building.
Currently, there is no mandatory requirement to provide embodied carbon information but there is mounting pressure for housing associations to provide such figures for their buildings. As social housing organisations seek to measure their whole carbon footprint, it can be difficult at the moment to compare the true embodied energy of the products they are specifying. However, manufacturers can provide independent certification from accredited bodies, such as Carbon Trust Certification, in order to validate the embodied carbon, or carbon footprint of their products. To date, Marley is the only roofing manufacturer in the UK to achieve independent carbon footprint certification for its product range.
Embodied carbon data does already form part of an Environmental Product Declaration, which looks likely to become the favoured method of environmental labelling in the UK in the future and this would help give specifiers a consistent method of comparing products.
Environmental Product Declarations
An EPD provides verifiable, accurate environmental information for products and their applications. It forms part of a series of European Standards prepared by CEN TC 350, providing a system for the sustainability assessment of buildings at the building level using a life cycle approach. Although they are widely used in other parts of Europe, most UK roofing manufacturers aren’t yet using EPDs but it looks likely that this process may be accelerated as a result of the changes to the CPR.
At the moment, EPDs can vary slightly according to the rules for product assessment that are used, and as the methodology defined in the recently published BS EN 15804* standard is still under review, up until now, most manufacturers in the UK have opted to await confirmation of the rules governing product assessment before embarking on accreditation.
Finally, the recyclability of products is becoming increasingly important in roofing specification for housing associations – not only the recycled content of the products themselves but also what happens to roof tiles at the end of their life.
Our pollution-eating Ecologic tiles are increasingly being used by housing associations, not only to improve environmental health but also because they have almost 50% recycled content. The tile has a unique ‘pollution-eating’ coating that absorbs Nitrogen Oxide (NOx) pollutants and converts them into soluble nitrates that are washed away harmlessly with rainwater.
With the UK now facing up to £300m in fines if it fails to improve air quality, we are encouraging all local authorities and housing organisations to consider using our EcoLogic roof tiles, which offer double the green benefit – high recycled content and pollution reduction.
End of life recycling is also becoming increasingly important as strict targets set by the EU Waste Directive require 70% of construction and demolition waste to be re-used, recycled or recovered by 2020. One roofing material that can help to achieve these waste targets is fibre cement slate because it can be fully recycled at the end of its lifetime and used to replace limestone and shale in clinker production, essential ingredients for Portland cement.
With all construction material specification, housing associations need to fully understand what impact a product has on the environment - not just what rating it has it in the BRE’s Green Guide to Specification but how it is sourced and the greenhouse gases it produces throughout its life cycle. Being able to demonstrate these credentials through environmental labelling is particularly important with the advent of Building Information Modelling (BIM), which must be used on all major projects in the public sector by 2016. Marley’s new range of fibre cement slate BIM objects are now available on our website to help housing associations and their contractors to model and prove the environmental impact of their roof.
* BS EN 15804 - ‘Sustainability of construction works – Environmental product declarations – Core rules for the product category of construction products’