Surpassing Net-Zero Carbon Goals

An exciting update on ZeroHouse: rather than being merely net-zero carbon, ZeroHouse actually removes carbon dioxide from the environment, giving it a negative carbon footprint!

So, what does it mean for the ZeroHouse to have a carbon footprint that is less than zero? It all comes down to the building materials used. Typically, the greenhouse gas emissions released when harvesting, processing, and manufacturing the materials used to build a house are underestimated. These emissions result in a huge carbon and energy footprint before the family living in the house is even taken into account!

Figure 1: Building Panels Stacked Side-by-Side Before Final Assembly

Figure 1: Building Panels Stacked Side-by-Side Before Final Assembly

Figure 2: Building Panel Being Assembled

Figure 2: Building Panel Being Assembled

You can check out this database, to see the embodied energy and carbon emissions of materials you might have in your home. The total carbon and carbon equivalent emissions from the ZeroHouse amounts to 6.991 metric tons, which results in an emission of 75.25kg of carbon dioxide per square foot. While this number may seem high, this emission value is already a 56% reduction compared to convention building standards, and we haven’t even taken sequestration into account!

The real accomplishment with our ZeroHouse is carbon sequestration. For those who do not know what that means, think of the ZeroHouse as a storage unit for emissions. By using plant-based construction materials, the carbon taken from the atmosphere when those plants were growing results in stored carbon within the building itself. This storage is in strong contrast with conventional materials that typically release carbon into the atmosphere when those materials are created.

Carbon sequestration is becoming a new trend in sustainable construction, with one recent example being the Borah Basin Building, the U.S.’s first public building made out of hemp! Brent Constantz, CEO of Blue Planet, recently pitched the idea of sequestering carbon dioxide into limestone, for use in highway construction. Right here at home in Canada we have Michael Green, Vancouver-based architect, advocating for the use of timber for big building construction, because of the added benefit of carbon sequestration.

Figure 3: An Interior Photograph of ZeroHouse

Figure 3: An Interior Photograph of ZeroHouse

Coming back to the ZeroHouse, our team was amazed to hear the news that a whopping 32.26 metric tons of carbon dioxide were sequestered in the building, leading to a net carbon footprint of 25.26 metric tons! This is due to the use of so-called “waste” materials, such as straw, wood, and cork, who’s carbon would have been cycled back into the atmosphere otherwise. For example, we got to see first hand how cork was used during our first visit to the ZeroHouse last month! You can check out the full details of how much carbon each building material sequesters in the figure below.

Figure 4: Chart of Carbon Capture for Each Material

Figure 4: Chart of Carbon Capture for Each Material

With building standards improving considerably over the years, the carbon footprint of building houses in general is improving, but we’re excited to be part of a project that far surpasses that goal! For a more detailed explanation of how the ZeroHouse sequesters carbon, check out this blog from our partner, the Endeavour Centre!