Embodied Carbon in our Buildings. What is it and what can we do about it?
We’ve all heard the term ‘embodied carbon’, especially of late. But what does it actually mean and why is it so important to understand its implications? Our Head of Sustainability Laira Piccinato explains.
Humans have been burning fossil fuels, a finite resource, since the late 18th century. This process releases greenhouse gases, the most important being C02 (carbon dioxide), although there are others which also have an impact.
C02 is a natural part of how our planet’s eco system works. It is released and absorbed through nature’s processes, in what is known as the ‘Carbon Cycle’.
The C02 emissions that we are releasing into the atmosphere through the burning of fossil fuels exceeds the capacity of our planet’s re-absorption mechanism, so we find ourselves with a surplus.
These un-absorbed greenhouse gases, the main one being C02, create a thick blanket in the earth’s atmosphere which prevents heat from escaping. This causes the earth’s temperature to rise, known as global warming, and this in turn causes sea levels to rise and increases evaporation, changing the earth’s weather patterns and makes them unpredictable.
What is the relationship between Embodied Carbon and the housing and construction sectors?
In the UK, the average C02 emissions per person is close to 10 tonnes per year – that’s the equivalent of around 100 car journeys from London to Edinburgh.
However, the construction and running of our buildings and cities – how we operate them – accounts for approximately 50% of the UK’s total annual C02 emissions.
When we measure C02 emissions in regards to buildings, what exactly are we measuring?
We need to consider two main calculations:
Firstly, Embodied Carbon: the carbon that is used in the extraction of materials, industrial manufacturing, transportation and installation of the building at its location. It is estimated that around 10% of a building’s carbon footprint sits within this category.
Operational Energy Carbon: the carbon in the energy used (and released) to enable our buildings and cities to function. This operation of our buildings uses predominantly fossil fuels – in order to heat them, have hot water, lighting, ventilation and cooling. Essentially, the energy used to keep us comfortable year round.
The operational energy of buildings in the UK accounts for approximately 30% of all UK C02 emissions.
What should the UK housing sector be doing to counter and lessen the amount of carbon used in our buildings and homes?
We need to strive towards building net zero carbon buildings.
We are in a climate emergency. If we continue to build our homes without making them energy efficient, and without taking into consideration the carbon released in the manufacturing and transportation of materials, our homes will continue to make the problem worse. If we don’t take action, as a society, we will continue to add to global warming and leave a negative legacy for future generations to deal with.
Over the next 40 years the global construction industry is expected to build the equivalent of Paris each week. We must make sure that the homes we build are sustainable to be lived in by the generations ahead.
How do we make our houses net zero carbon?
A new house with ‘net zero operational carbon’ does not burn fossil fuels in its running. It is 100% powered by renewable energy, either generated on site via PV panels for example, or via a de-carbonised energy grid (which we will talk about in this series in a future Blog). And a net zero operational carbon house will achieve a high level of energy performance.
In addition, during the construction process, the house will have been built with the national embodied carbon targets in mind, and at the end of it’s life, can be disassembled in accordance with the circular economy principles.
HollandGreen’s objectives and targets to play our part in creating net zero carbon homes.
We’re working hard to design homes that use less carbon – either embodied in their build or in their operational running. There’s a long way to go, but every day we are reminded of our commitment and responsibility, and this was underlined recently in April 2023 by the World Earth Day initiative.
We are working to meet the RIBA 2030 Sustainable Outcomes initiative, aligned with these targets to deliver projects that vastly reduces energy consumption and are ‘zero carbon’. Currently working on our strategy and plans, we look forward to sharing our RIBA 2030 plans soon.
We’re also delighted to be a partner of the wonderful UK charity Woodland Heritage, offsetting the carbon used in our projects by planting trees in British Woodlands through donations to their initiatives.
We have a ‘Fabric First’ approach for every new home design. This means we ensure the walls, floors and roofs are designed to the highest standards with the most efficient insulation values we can feasibly achieve within the project. We make sure that solar gains are mitigated, natural light is maximised and energy is not lost. This means we know we have a good design at the building’s heart.
Every one of our new home projects has some element of sustainable technology as standard – be that heat pumps, micro power generation and batteries to store that power such as Tesla Power walls, or MVHR systems – that’s ‘mechanical ventilation with heat recovery’, delivering fresh filtered air into a building while retaining the energy used to heat it.
Addressing Embodied Carbon in big picture thinking.
I see a future with newly built homes so energy efficient they generate more energy than they consume, and their surplus energy is distributed via the national grid. A future where, as a country, we create new housing stock that can be part of our nation’s power generation strategy, therefore turning a problem into an opportunity.
Our goal is that the design of our clients’ homes at HollandGreen will be part of this solution and future, and it’s a really exciting prospect. If all new homes acted as mini power stations, imagine the impact that would have not only to our collective fight against climate change, but also to the UK’s energy demand. I think it’s a win-win objective to work towards.
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