Global warming is a hot (pardon the pun) topic right now – with the recent devastating effects of Hurricane Harvey, Irma and Maria, sparking increasing debate about climate change. Now, more than ever, is the time to really consider how we’re impacting this planet – and that means thinking about the materials you use when it comes to construction. Whether or not you ‘believe’ in global warming is a matter for another day, but surely only good can come from thinking a bit more long-term?
We often see the word ‘sustainability’ tossed about, but what does it really mean? The term originally comes from forestry, and stipulates that the amount of wood taken from the forest must not exceed the amount it can regrow. Thus, a sustainable material is one that does not deplete non-renewable or natural resources, or whose use has no adverse impact on the environment. But in short, sustainability is all about something being able to last.
Whilst durability and strength will obviously be key factors when choosing your building materials, environmental impact should also be taken into account. The production of just one tonne of reinforced concrete emits 198kg of carbon dioxide – one of the main ‘greenhouse gases’ responsible for climate change – whilst making one tonne of steel emits 1.46 tonnes. This is a massive amount, which is why you need to start considering alternative options, if you haven’t been doing so already.
Of course, switching to more sustainable materials does provide some challenges – including persuading the client, for the first part. It’s no secret that many sustainable materials may initially have a greater outlay. And guaranteeing the material quality and performance could also be an issue, as well as ensuring a ready supply of them.
But sustainable materials aren't just good for the environment. The fact is they could save your client money in the long run, by providing buildings that are more energy efficient – so perhaps lead with that when trying to convince them to ‘go green’. Not to mention, sustainable materials emit fewer (if any) toxins, making them much safer to build with - improved bio-based materials can even improve the internal air quality of buildings by interacting with and removing airborne pollutants.
The good news is there are a number of different ways you can build more sustainably. The first step is to plan ahead, and to design with deconstruction in mind. Rather than taking a linear approach, where materials are thrown away immediately after use, you should aim towards creating a ‘closed-loop’. This means following the procedure of: extract, process, manufacture, use, reuse (as many times as possible), dismantle or disassemble, recycle (again, as many times as possible), and then finally throw away, only when no further use remains.
Using less by not over-specifying performance requirements, or matching demand to supply, are also simple ways to ensure you help preserve natural resources and create less waste. Additionally, you can reduce the impact of using construction materials on the environment by lessening the transport of materials – meaning the associated fuel emissions will be lowered.
Beyond this, you should be seeking to reuse materials, or even components in situ wherever possible. For example, you could reuse and build upon the structural frame of a building, such as the foundations or existing ground floor slab.
Using reclaimed materials, or components which require minimal processing will also allow you to build more sustainably. Crushed glass can be used as bedding material for paved or block surfaces, whilst demolition arisings (such as crushed aggregate) can be used for landscaping or backfilling excavations, for instance. Additionally, steel tube from the oil industry can be used for piles.
These days, there are plenty of alternatives available for the likes of concrete and steel, with a lower environmental impact – so you should be looking to use these substitutes wherever possible. Green materials such as grasscrete, rammed earth, Hempcrete, bamboo, recycled plastic, wood, mycelium, ferrock, ashcrete and timbercrete all offer great alternatives to concrete, for instance. Equally, good quality housing can be built from structural timber with a bio-based insulation, such as straw or other cellulose fibres.
It is actually also surprisingly easy to use materials or components with significant and known recycled content (RC). In fact, building entire construction works with more than 20% RC is highly attainable – and was even achieved at the 2012 London Olympics site. Plastic street furniture, such as bollards and barriers, are often made from 100% RC plastic. Equally, decking can be made from 100% RC ‘plastic lumber’ that looks like timber.
There are a huge number of environmentally friendly alternatives available, in place of more widely used construction materials. So there’s really no reason not to start thinking a bit more sustainably. After all, if you can contribute to saving the planet – and save your client money in the long run – just by taking responsibility and working with the future in mind, then why on earth not? Not to mention, your working conditions will become much safer by switching to ‘green’ materials.