Let's talk about embodied carbon
and how to reduce it.
An architect's manual for reducing
the carbon footprint in designs.
Assignment:
Research on embodied carbon and the environmental impact on the housing sector, resulting in the Carbon-Based Design publication.
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Year:
2021
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Client:
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Team:
Martin Sobota, Isabel Driessen (Cityförster),
Thomas Wellink , Menno Brouwer (RVO), Margot Holländer (MOR Studio)
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CO2 emissions of the built environment are an urgent challenge.
“Embodied emissions are usually a blind spot”
Both operational and embodied emissions need to be reduced drastically, to tackle climate change.
What are these two types of emissions?
Operational emissions happen during the use phase of a building. Heating, cooling and lighting are some examples. Today we see that there is sufficient knowledge of designing energy-efficient buildings.
Embodied emissions however, seem to be a blind spot. Those emissions happen during the production of materials and the construction phase of a building.
Through this research we wanted to make architects aware of these hidden emissions and present some guidelines to reduce them.
The so-called Milieu Prestatie Gebouwen (MPG) is a mandatory way of calculating the embodied impact of new buildings in the Netherlands. Have you heard of it?
We encourage you to have a look into the MPG calculations of projects. Try to understand the origins of embodied emissions and look for ways to optimize the results.
In the CBD report, we did just that. We critically assessed the calculation method, looked into alternative materials and different design solutions.
Guidelines for architects
to reduce carbon footprint
Basic rules.
The R-ladder “Refuse, reduce, reuse, recycle” is a good rule of thumb. The best option is to build less, renovate more and reuse what we have. The less we build new, the fewer emissions we cause. With one exception:
Timber is a great structural material.
Sustainably sourced timber captures CO2. Structural components typically have a large mass and long lifespan, effectively storing large amounts of CO2 for a century.
Today, or 50 years down the line?
Keep an eye on the time-component, when you assess emissions.
The next 30 years are critical on the roadmap towards the 2050 Paris Agreement goals. The use of high-carbon building materials today has a long-lasting effect that cannot be undone.
When are emissions made?
The location of a building matters.
Inner-city projects can make use of the existing technical infrastructure, public transport and shared facilities. Newly connecting a project in a rural setting might hold hidden environmental costs.
Where should we build?
Reduce glass.
The production of glass causes large amounts of carbon emissions. Avoid glazing where it is unnecessary. This can be a tricky architectural choice to make.
Cement is poured as part of most building's floors. The problem: It is high in embodied emissions and non-reusable. We should explore alternative solutions: Bio-based construction, circular and industrial construction.
Keep photovoltaics.
They generate renewable energy and reduce the building's operational emissions. Even though emissions are made in their production phase, which will increase the MPG score, they pay off after a few years.
Cement.