In the plan for its Waste Prevention Programme for England, the Department for Environment, Food and Rural Affairs (DEFRA) highlighted1 that the UK construction sector uses more resources than any other sector. In fact, England alone generates over 60 million tonnes of non-hazardous waste every year. Furthermore, acquiring the wide range of resources that the industry needs has contributed to climate change, deforestation, habitat loss and pollution. Added to this is the concern that many raw materials are finite and increasingly difficult to obtain.
Designing, constructing and deconstructing buildings in a way that keeps resources in use for as long as possible will help address these issues in a number of ways. Procuring raw materials is energy intensive and damaged to the environment, and where it cannot be sourced locally, the carbon impact of obtaining the material is magnified by the transportation.
In contrast, recycling the materials can often be carried out relatively locally and, depending on the material, typically requires far less energy. Additionally, reusing or recycling components removed from buildings will divert materials away from landfill or disposal, helping to address the industry's contribution to waste and significantly reduce the volume produced by the UK.
When looking to maximise the circularity of a building, selecting the right materials is crucial. Aluminium has many sustainability advantages and its natural corrosion resistance and excellent weight to strength ratio means it can be used for everything from roofs and walls, to windows, doors and curtain walling.
Also, if the aim if to create a circular economy, aluminium is ideal. Unlike other materials, it is endlessly recyclable with no degradation in quality and is easy to separate from other waste. That means that when a building reaches the end of its lifespan, a large proportion of the aluminium components can be recovered and recycled. As an example, when the old Wembley Stadium was demolished in 2003, 96% of the aluminium was recovered for recycling, including all of the aluminium from the roof structure.
A further advantage of aluminium is that melting it down for reuse requires only 5% of the energy needed for primary aluminium production. This means that products made with recycled aluminium have a much lower carbon footprint and will contribute to lowering the embodied carbon of the building as a whole.
In addition, aluminium has the potential to be used in very large volumes as it is produced from Bauxite ore, one of the most abundant raw materials on the planet. This means that, while not endless, there is a sufficient supply of aluminium for it to be used widely if managed correctly through the principles of a circular economy.
Despite these clear advantage of recycling aluminium and the progress that has been made in recent years, there is still more that can be done to improve its recovery and reuse. The Council for Aluminium in Buildings (CAB), of which TECHNAL is a member, has launched its Closed Loop Recycling Scheme to help maximise the opportunities in construction. The scheme aims to improve the quantity and quality of recovered aluminium scrap available in the UK and keep aluminium in use as a 'permanent material'.
At TECHNAL, to support specifiers in designing for a circular economy we are using Hydro CIRCAL® 75R aluminium in an increasing number of door, window and curtain walling products across our portfolio.
Hydro CIRCAL® 75R contains a minimum of 75% recycled end-of-life aluminium (post-consumer scrap), from the likes of façades and windows that have been removed from buildings. As a result, it has one of the smallest CO2 footprints of any aluminium worldwide with 2.3 kg of CO2 emissions per kilo of aluminium. This is 86% or 7 times less than the global average for primary extraction.
The construction industry will face a number of challenges in the coming years. Among these is the need to cut carbon emissions to limit the impact of climate change as well as an expanding global popularion that will increase the demand for key building materials. Establishing a circular economy across the sector will require a shift in approach, however, the nature of materials such as aluminium means that there is a simple first step that can be taken through the specification of responsibly sourced products.