Let's talk about embodied carbon and how to reduce it.

An architect's manual for reducing the carbon footprint in designs

pexels-pixabay-355802__edited.jpg
pexels-pixabay-355802_.jpg

Assignment:

Research on embodied carbon, resulting in the 2021 publication Carbon-Based Design. Onderzoek naar de milieuimpact van de woningbouw.

Year:

2021

Client:

Cityförster, RVO

Team:

Martin Sobota, Isabel Driessen (Cityförster),
Thomas Wellink , Menno Brouwer (RVO), Margot Holländer (MOR)

CO2 emissions of the built environment are an urgent challenge.

“Both operational and embodied emissions need to be reduced drastically, to tackle climate change.”

Both operational and embodied emissions need to be reduced drastically, to tackle climate change. Carbon-Based Design illustrated the importance of embodied emissions and how to reduce them. What are these two types of emissions?

 

Operational emissions happen during the use phase of a building. Heating, cooling and lighting are some examples. Architects of today have expanded their knowledge on designing energy efficient buildings. Embodied emissions on the other hand seem to be a blind spot. It is a topic we wanted to explore and shine a light on. Embodied carbon emissions happen in the production and construction phase of a building and its materials. In this report, we show how architects can become aware of these hidden emissions and how they could reduce them.

CBD_1.png
CBD_4.png

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?

 

Is it a tool you use during the design process? Even though the MPG is a good initiative, it is not a user-friendly tool for sustainable architecture just yet. We encourage you to have a look into the MPG calculations of projects. Try picking them apart, understanding the origins of embodied emissions, and looking 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.

Here are some of the most important takeaways:

24 guidelines to reduce architecture's 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 can not be undone.

When are emissions made?

CBD_3.png

The setting of a building matters. Inner-city projects can make use of the existing technical infrastructure, means of 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.

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.

CBD_2.png

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, low-carbon and demountable.

Cement.

To learn more, find the complete report here (in Dutch)