12 World Green Building Council: EU Policy Whole Life Carbon Roadmap These issues are compounded by forecasted population growth. This will increase demand for floor space, making greater energy and resource efficiency an even more pressing concern. The total global floor area of buildings is estimated to double by 2060, with over 50% of that increase likely to occur within the next 20 years. 9 Asia and Africa will see particularly rapid growth in new buildings, while Europe faces a different challenge: an ageing existing building stock. It is thought that up to 80% of buildings that will be in use in 2050 already exist. Indeed, about 35% of the EU’s existing buildings are at least 50 years old, and 97% are not efficient enough to comply with future carbon reduction targets. The current energy crisis, aggravated by the Russian invasion of Ukraine in February 2022 provides a compelling reason for accelerating decarbonisation and energy security. Russia supplies 40% of Europe’s gas, and while some seek alternative energy sources, the renovation of buildings should not be overlooked as a solution. Increasing buildings’ efficiency will reduce reliance on external resources, making this a cost-effective way to bolster energy security. Recognising this potential, the EU has published a plan in response to the crisis (REPowerEU). It outlines how the EU can reduce dependence on Russian fossil fuels before the end of the decade and replace them with stable, affordable, reliable and clean energy supplies. One focus of REPowerEU is to renovate more buildings to reduce energy consumption, double the planned deployment of heat pumps and install more smart meters. These challenges in the built environment also present opportunities, and both the public and private sectors have key roles to play in accelerating action and ambition. As more businesses act to tackle climate change, they encourage governments to advance their policies to give the private sector further clarity on the direction of travel. Public leadership (ie government) and private leadership can thereby elevate climate action through a phenomenon known as the ‘ambition loop’ to deliver on the goals of the Paris Agreement and the Sustainable Development Goals. Understanding operational carbon Operational carbon refers to the carbon emitted during the operational or use phase of a building. It includes emissions from fuel and electricity use, refrigerants and certain maintenance activities. Accounting for 36% of EU emissions, this operational impact of Europe’s building stock is a major contributor to climate change and provides an opportunity to tackle the built environment’s WLC. To do so, both new and existing buildings must be considered. Europe has many old, energy-inefficient buildings. Renovating these existing buildings to make them more energy efficient can vastly reduce their operational carbon footprint, and the technology to do so efficiently and deeply already exists. 10 Possible measures include installing insulation, renewable heating systems and better windows. Decarbonising buildings’ operations could also create jobs and tackle social issues like energy poverty. New buildings, on the other hand, can be designed to minimise operational emissions from the start, ensuring they are zero- emission buildings (ZEBs) or Nearly zero-energy buildings (NZEBs) and that they will require no future renovation work to improve their performance. When tackling operational carbon, however, the embodied emissions of the materials and processes used must not end up increasing the WLC impact of a building. Understanding embodied carbon Embodied carbon emissions, which amount to 3.67 million tonnes of carbon dioxide (2019) worldwide, are attributed to the construction, renovation, deconstruction or demolition and the wider supply chain of a building. In other words, before a building is even used, it has already contributed substantially to carbon emissions and depleted our ‘carbon budget’. As this so-called upfront carbon cannot be reduced once a building starts operation, addressing these emissions is even more important if nations are to transition to zero emissions by 2050 at the latest, with substantial contributions this decade (approximately 50% reduction in global emissions by 2030). 11 Embodied carbon is estimated to contribute between 10–20% of the EU’s building carbon dioxide footprint, depending on factors such as building type and construction technique and materials. In countries with low-carbon energy, the embodied share can already be as high as 50%. 12 Indeed, as buildings become more efficient and the energy supply is decarbonised, the relative share of embodied emissions will increase. Several factors affect the amount of carbon emitted at each stage of a building’s life cycle. 13 However, in general and for new buildings, a great portion of these emissions come from the product and use stages, as shown in Figure 1. 14 9 IEA (2017), Global Status Report. 10 BPIE (2017), 97% of buildings in the EU need to be upgraded. 11 IEA (2021), Net Zero by 2050: A Roadmap for the Global Energy Sector. 12 Material Economics (2019), The Circular Economy - a Powerful Force for Climate Mitigation. 13 WBCSD & Arup (2021), Net-zero buildings: Where do we stand?. 14 Institution of Structural Engineers (2020), How to calculate embodied carbon.
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