Beneath the Surface: The True Cost of Building Materials
Behind construction materials lies a vast, often overlooked network of quarries, forests, and mines. The origins of individual material components are rarely considered, yet they carry major consequences.
In 2022, the construction industry accounted for 34.5% of the EU’s raw material consumption 1, a figure that calls for greater awareness of where and how these resources are extracted. It is at this stage of extraction and processing that biodiversity loss is often most acute. Understanding the sourcing and use of these materials is essential for monitoring environmental, socio-economic, and the impacts of resource depletion.
Steel production illustrates this complexity well. Primary steel manufacturing relies on three core raw materials (iron ore, coal, and lime), alongside at least ten additional elements used for alloying 2, sourced globally. Iron ore is predominantly extracted from Australia, Brazil, China, India, Russia, and South Africa. In 2024 alone, Australia produced 930 million tonnes of iron ore, with Brazil contributing a further 440 million tonnes 3.
Iron ore is typically extracted through open-pit mining, which involves clearing topsoil and vegetation to access the material beneath. This means huge areas of land are cleared, leading to a loss of habitat and creating an impact throughout the ecosystem. Species lose their homes, and their food sources are depleted, leading to a change in the delicate balance of the local biodiversity, which can in turn lead to the potential extinction of species 4. In a lot of areas where these mines are located, there is water scarcity, the process for iron ore extraction requires a significant amount of water, so this can exacerbate the local issue even further.
Other impacts include the contamination of large quantities of water and the release of harmful dust and particulate matter, having an adverse effect on the health of nearby humans and animals. The impact of open pit mining continues even after the mine is no longer in use, often leaving scars on the landscape of large, uninhabitable pits and waste piles that continue to leach toxic materials into the environment 4.
Limestone can be sourced from across the UK, primarily in the Pennines, South/North Wales and parts of North Yorkshire and Cumbria 5. It is converted into lime for steel production through calcination, a process that involves heating to around 900˚C 6. Lime is used in many construction processes, but within steel, it is used to remove impurities such as silica, phosphorus and sulphur from molten iron, forming slag. Like Iron Ore production, limestone is extracted through open-pit mining. Limestone quarrying can have severe environmental impacts due to limestone forming the basis of certain habitats due to its chemical composition. This makes these habitats very hard and sometimes impossible to restore 7.
To mitigate these issues and reduce the impact of your choices, there are a series of considerations that can be followed. This includes using what we already have and prioritising the use of existing steel structures and avoiding the need for virgin materials to be used. Reducing the need to extract the raw materials in the first place and having an awareness of the impact of our design choices is vital 8.
Every material used has an impact further than what is initially seen. Even if the final product is manufactured near the site, the additional impacts need to be considered and recognised. All the components that make up a product have an impact that needs to be recognised.
