The trade associations, enthusiasts and lobbyists for different building materials are busy telling us how sustainable their material of choice is, and how it out-performs all others. Amongst the myriad claims, facts and figures, how can we establish which material is the most environmentally friendly? And is that even the right question to ask?
Timber is a natural material and absorbs CO2 while it grows, steel is eminently recyclable, concrete is ideal for thermal mass construction, whereas bricks are durable and can be reclaimed.
Even if we discover which has the lowest embodied carbon, for example, we may not agree on what sustainability actually means. Are we talking about cradle-to-grave lifespans, economic viability, wildlife considerations, energy performance, aesthetic impact, recyclability – or even taking a holistic view of the building’s use and social sustainability within a local community?
In the absence of a unified framework of assessment and an agreement on relevant metrics, the debate will continue.
At the end of the day, each project needs its own, tailored assessment. A good designer will select from all options and choose what is fit for purpose, rather than become too attached – by habit or preference – to one material or another.
But in order to make that choice, we need a level-headed view of the facts available for each material, accompanied by real-life case studies. We also need to consult with people who are in the know about the different accreditations and codes, and can give an unbiased overview. Below are some sources that make a good start.
Codes and certifications: consultancy
- Mel Starrs, Associate Director at PRP Architects, specialises in sustainability and green buildings. Her Elemental blog is full of useful information.
- The CodeStore.co.uk has a directory of CSH consultants and assessors. Materials is number 3 on the Code’s list of 9 sustainable design criteria.
- Jennifer Hardi works for the BRE’s Low Carbon Future team and is also part of the technical support team for the Energy Saving Trust’s Best Practice Helpline.
- Bruno Miglio is a Leader of Global Materials Science at Arup. The team offers advice on the use of materials in engineering and architecture – from design to reuse or demolition.
- The BRE’s Green Guide to Specification assesses building materials and components in terms of their environmental impact across their entire life cycle.
This is Concrete showcases sustainable construction projects and encourages project-based feedback, presenting case study evidence to support the sustainability credentials of concrete.
Sustainable Concrete has information on concrete production, performance and end-use, and provides indicators on materials efficiency.
MPA (Mineral Products Association) runs the Concrete Centre, which contains news, publications, webcasts, online services, advice and design tools.
The BCSA is the national organisation for the steel construction industry. Its website, SteelConstruction.org, has a section dedicated to sustainability. The BCSA’s Target Zero project “will generate costed solutions for structural steel framed construction that achieves highest BREEAM ratings and changes to Part L of the Building Regulations, meeting emissions reduction targets towards zero carbon by 2019.”
TRADA has a library of downloads that detail the sustainability of timber. The Association’s Technology Assessed scheme also helps establish whether a company’s literature gives a fair representation of the benefits and characteristics of a product or service – a useful tool against greenwash.
The Forestry Commission also provides comprehensive facts and figures on the timber trade.
All members of the Stone Federation of Great Britain have to comply with this Sustainability Statement. The Federation provides a Technical Advice Service for the commercial and domestic use of natural stone.
Stephen Critchley – a Master Stonemason in Central London – is a font of knowledge on ancient and modern uses of natural stone, giving talks, workshops and demonstrations.
The simplest view of the sustainability of natural stone – there is tonnes of it about and it lasts for a very long time – is outlined here by CED.
Bricks and blocks
Bricks, in the words of the Brick Development Association, are “a versatile and durable building material, with excellent life cycle performance, energy efficiency, high thermal mass and responsible manufacturing.” Its publications on the sustainability issues of bricks and brickwork are listed here.
Sustainable Build details the manufacture and use of bricks as a sustainable building material in this article, and also comments on stone vs brick.
What other sources have you found useful for determining the sustainability of specific building materials? Please leave a comment and let me know!
This post was inspired by an interesting conversation on Twitter with structural engineers David Sharpe and James Thomson.
Compare and select building materials on ESI.info