Embodied Carbon

The Carbon Footprint You Can't See in Your Home.

Everything we do, especially making our homes more energy efficient and sustainable, impacts the environment. We often think about saving energy and using clean energy in our homes. But the materials we use to renovate also matter. As a homeowner, it's important to think about all the effects of making your home energy efficient. That's where embodied carbon comes in.

What Is Embodied Carbon and Why Is It Important?

Embodied carbon is all the greenhouse gases released when a product or building material is made. This includes the emissions from taking raw materials from the earth, manufacturing them in factories, transporting them, and installing them. Think of it as ‘upfront carbon’ – the emissions produced before the material even reaches your home.

Knowing about embodied carbon helps us see the real environmental cost of the products we use in our homes. When we think about all the emissions from start to finish, we can see the true environmental cost.

What Is the Difference Between Embodied and Operational Carbon?

Embodied carbon is the carbon released when building or renovation materials are made and moved. On the other hand, operational carbon emissions are the emissions produced during day-to-day use such as heating, cooling, and lighting. Unlike operational emissions, the impact of embodied carbon is fixed when you build or renovate and can't be changed later.

Should We Consider Embodied Carbon During a Net Zero Retrofit?

The materials and ways we renovate can sometimes create a lot of embodied carbon, so it's important not to reduce operational carbon by using materials with a high carbon footprint. The goal of a Net Zero retrofit is to significantly reduce the carbon emissions from your home's operation by using less energy overall and switching to renewable energy sources like electricity. Unlike other emissions you might offset, you can't create more fossil fuels to balance out their use, so the only true path to Net Zero is to stop burning them altogether. This means choosing plant based materials rather than petroleum based materials.

Does Embodied Carbon Really Matter?

Absolutely! Depending on the materials used, it’s possible that a building has more embodied carbon in its construction than it will ever use during its operational lifetime.

Even if we reduce operational carbon emissions, the impact of embodied emissions can still be significant. Embodied carbon can be responsible for a large portion of a building’s lifetime carbon emissions. This means that the materials used in construction play a crucial role in determining a building’s environmental impact. Buildings represent a massive opportunity as some construction materials are carbon-sequestering, which means they can remove carbon from the atmosphere. Construction is one of the few industries that has the potential to be part of the solution by creating carbon-storing buildings that also have low operational emissions.

Which Materials Have High or Low Embodied Carbon?

When planning a Net Zero home renovation, it is important to think about the materials you choose and their embodied carbon. It is better to avoid products that produce more carbon to make than they will ever save.

For every type of material, there are choices with different amounts of embodied carbon – high, medium, low, and even some that store carbon. For instance, making foam insulation produces a lot of carbon, which can cancel out the carbon it saves by using less energy. So, it's a good idea to pick plant-based insulation that stores carbon and also helps you save energy (and therefore reduces operational emissions) for heating your home.

Did you know that 5-20% of the weight of foam insulation is flame retardants, making it a highly toxic material that should not be used in homes!

Natural materials such as wood fiberboard, bamboo, hemp, cellulose, waste textiles, straw, or wool store carbon. This means that they absorb and store carbon from the environment, helping to reduce your carbon footprint. By insulating your home with these materials instead of foam insulation, you contribute to storing carbon rather than creating it. Plant-based materials are just as energy-efficient as foam insulation in reducing your operational carbon emissions. They are also better for both your health and the environment.

How Is Embodied Carbon Calculated?

Calculating embodied carbon requires understanding all the materials, or ingredients, in a product and all the activities involved in their creation, such as processing

and transport. Embodied emissions can be calculated using tools such as the Building Environmental Assessment Method (BEAM). However, you don’t need to calculate this yourself. Homes to Zero can do it for you! In the Net Zero Plan and Retrofit steps we help homeowners select low embodied carbon materials for their retrofit.