With the construction industry responsible for a third of the world’s total waste, Scott Martin from Mumford & Wood asks when is the sector going to take responsibility
The industry’s monumental output of non-biodegradable and often hazardous materials has been linked to several environmental issues, including soil degradation, water pollution and air contamination. They also contribute to climate change due to the emission of greenhouse gases during both production and disposal.
There is increasing pressure on the industrial sector globally to take more responsibility for the materials used in both construction and manufacturing. For example, the UN’s most important actions for industry include full decarbonisation of industrial production; reduce material waste and recirculate materials; and reduce demand and enhance access to energy efficient, material efficient and CO2 neutral materials.
And the UN’s most important actions for construction itself include creating an efficient building shell, and scaling up zero-emissions heating and cooling technology. The choice of building or product materials can greatly affect future environmental changes. Often, the recyclability of the material is the key consideration, but the entire ‘cradle to grave’ journey is equally important and often overlooked.
Why is ‘cradle to grave’ so important?
To find out, let’s look at a typical product manufactured for the construction industry – windows and doors.
It’s probably obvious, when looking at materials such as aluminium, timber and plastic, which presents the more sustainable option.
We know that around 43% of PVCu is from petroleum and currently around 80% of all plastic is not recycled and destined for landfill. The recyclability of aluminium is significantly better at around 95%. However, the Building Research Establishment Environmental Assessment Method (BREEAM) found that wood is the only truly sustainable and renewable building material available. In fact, a report by Heriot Watt University shows that timber frames are carbon negative, and will save 160 kg of CO2 over their lifetime compared to PVCu. But this needs to be qualified; just using timber doesn’t mean these figures are achieved.
Sourcing
Understanding where materials come from is incredibly important, and the transparency of this depends on the level of care being taken along each stage of the product journey. We are extracting 100 billion tonnes of raw material from the planet every year. So how is this managed?
For timber extraction, forest stewardship, logistics considerations, manufacturing efficiencies, recycling, and waste management all need to be considered.
Sustainability certifications are an important tool for architects and building professionals to evaluate and improve the environmental impact of buildings. ISO 14001 & 50001 is one such certification. Another is Forest Stewardship Council (FSC) certification, which guarantees that the wood used in a building project has been sustainably harvested and managed. This certification aims to ensure that forests are managed in a way that preserves biodiversity, reduces the risk of deforestation, and supports the livelihoods of local communities.
Another certification that’s widely used in the industry is BREEAM, which evaluates and rates a building’s environmental impact based on factors such as energy use, water efficiency, materials, waste, and health and wellbeing of the occupants. BREEAM certification is recognised globally as a standard for sustainable building design and construction.
Logistics
Delivery of wood is one of the areas that companies have the least visibility of and where many of the emissions come from. The Department for Transport suggests that 29% of HGVs on the road are empty. In order to reduce this, it is important to plan so that each delivery is full and that space is maximised to reduce the number of deliveries required. Also, shortening the supply chain by sourcing locally helps.
Waste
Manufacturers can reduce waste by using set lengths, and minimising waste by getting the most out of a single length, and optimising pallets and manufacturing lines.
It is possible to recycle 100% of timber waste and keep it out of landfills. With the right equipment many by-products from production can be recycled into usable lumber, or turned into fuel for power stations. Additionally, businesses that process timber can send their waste to be chipped and used for mulch in gardens or landscaping projects. By recycling timber waste instead of throwing it away, we can reduce the amount of energy needed to produce new resources from scratch.
Lifespan
The lifespan of a product or material should also be considered in this journey. Despite aluminium being nearly 100% recyclable, its typical lifespan is around 30 years and PVCu just 15 to 25 years. However, with correct maintenance, timber can last up to 60 years. The longevity of material not only supports being more sustainable, but also contributes to lower overall costs in building.
Solution
In order to improve the sustainability of our building projects, we need to ensure that materials are sourced from sustainable sources and delivered in an efficient way. It’s clear that timber can play an important role in our efforts towards sustainable practices in the construction industry, but total transparency of a materials origination, manufacturing technique, delivery, installation and recycling is essential.
Scott Martin is sales director at Mumford & Wood