Embodied carbon vs operational carbon: What’s the difference and why does it matter?
The building sector to take a holistic approach to tackling its climate impact – and that involves looking at both embodied and operational emissions, explains Steve McGregor, group MD of DMA Group
As we head towards the highly anticipated 26th UN Climate Change Conference of the Parties (better known as COP26), the light being shone on net zero has never been brighter.
The summit, held in Glasgow and Milan, is expected to play a large part in defining the premiership of UK Prime Minister Boris Johnson, who has pledged his commitment to work with all countries and join forces with civil society, companies, and people to inspire climate action.
Indeed, climatic events of the past couple of years have created a growing sense of urgency. Just prior to the outbreak of the global COVID-19 pandemic, Australia witnessed some of the worst bushfires in its history, while July this year saw several European countries suffer devastating levels of flooding caused by unprecedented volumes of rainfall.
These extreme weather events, from droughts and hurricanes to flooding and wildfires, are occurring with increasing severity and frequency at a time when Arctic ice sheets are splintering and rainforests shrinking. Indeed, the time for truly joined up action between public and private spheres around the world, is now.
The two types of carbon
Cutting carbon emissions and building a net zero society is widely seen as the best way to mitigate the challenges posed by climate change.
The UK government had stated its mission to reach net zero emissions by 2050, making it the first major country to legislate for such a goal – something Boris Johnson, no doubt, wants to see other nations pledge at COP26.
Carbon emissions can broadly be categorised into two major bands.
Embodied carbon translates into all the carbon dioxide emitted in producing materials. It is estimated from the energy used to extract and transport raw materials, as well as emissions from manufacturing processes.
Looking at buildings specifically, the embodied carbon of a construct can include all the emissions from the construction materials, the building process, and all the fixtures and fittings inside. Furthermore, it also covers emissions from deconstructing and disposing of components at the end of its lifetime.
Embodied carbon is an important barometer through which to strategise and measure net zero action.
Urbanisation is accelerating across the globe – by 2050, more than two-thirds of the world population will live in urban areas, meaning architects and developers must prioritise reducing carbon emissions during the design and construction of new builds.
However, what is often overlooked is the environmental footprint of our current building stock.
This is where focus on operational carbon enters the picture. Operational carbon is the amount of carbon emitted during the operational or in-use phase of a building, which can include the use, management and maintenance of a product or structure.
Currently, it accounts for 28 per cent of all global greenhouse gas emissions, compared to the 11 per cent stemming from embodied carbon.
A brighter spotlight therefore needs to be shone on operational carbon. The World Green Building Council’s Net Zero Carbon Buildings Commitment is a good example to follow, as it factors in equal embodied and operational carbon weighting into its approach.
Its requirements (geared towards net zero by 2030) are certainly bold. But they represent the sort of ambition that is needed to make meaningful progress.
Taking operational carbon seriously
It is estimated that some eight in 10 of the buildings that will be standing in 2050 have already been built, meaning any local, national or international strategies to reach net zero simply must factor in making our current stock more sustainable.
This means that property developers, owners, occupiers and policy makers must now determine the best means to improve the energy performance of their buildings.
There are many ways this can be approached, the most obvious being to reduce the amount of energy required to maintain optimum temperatures. Here, investment in double (or even triple) glazing and insulation solutions – two of the most effective solutions – is increasing rapidly.
In 2020 the worldwide market for building insulation reached $28.3bn, yet by 2028 this is predicted to surpass $38.4bn. And such growth could be even steeper if restraints including fluctuating raw material prices and a lack of workforce are addressed. Where energy is needed within buildings to heat or cool them, renewable sources offer another way to reach net zero.
In the UK, well-documented gas shortages are causing panic among businesses and consumers about rising prices. This makes it imperative that alternative, sustainable sources of energy are brought online in greater volumes – in terms of buildings, solutions such as heat pumps and hydrogen (or part hydrogen) boilers are entering conversation about decarbonising the gas grid.
Smaller-scale solutions will also play their part, be it switching to LED lighting, installing hot water alternatives, educating employees and residents, or even adopting smart building management tools and processes. These can include the use of sensors to forecast and respond to varying levels of building occupancy, and adjusting heating, cooling and lighting output accordingly.
Indeed, from what we are seeing on the ground, it is clear that developers and buyers are becoming increasingly keen to leverage energy management, carbon technology and renewables.
This is critical if the building sector is to play its part in progressing towards net zero, both from an embodied and operational carbon perspective.
Steve McGregor is group MD of property services specialist DMA Group
