The world's first carbon-absorbing concrete house

The house in the mountains has a unique design with 3m high walls built from about 2,050 carbon absorbing concrete blocks .

The house has 5 retaining walls made from CO ₂ absorbing concrete . (Video: Design Boom)

A house in Karuizawa, a mountain town near Nagano, Japan, has walls made of the world's first CO2 absorbing concrete called ₍ CO2 -SUICOM ) , Interesting Engineering reported on April 8 _. . The house is located along the road, in a 110m long plot of land. Karuizawa is one of Japan's oldest and most famous mountain resort towns.

This new type of concrete is made by replacing part of the cement with an industrial by-product, while adding CO ₂ absorbing materials , thereby reducing emissions from the production process. They are jointly developed by the companies Kajima, Chugoku Electric Power, Denka and Landes.

Absorbed CO ₂ is held firmly within the concrete and will not escape into the atmosphere.

The strength of CO2 absorbing concrete _is equivalent to that of regular concrete . To fabricate, shaped concrete is placed into a curing chamber. Then, CO ₂ is pumped into the chamber for absorption by the concrete. CO ₂ from various sources can be used directly. While conventional concrete blocks emit about 300 kg CO ₂ per m ³ , CO2-SUICOM can achieve carbon neutrality (the amount of carbon emitted equals the amount of carbon absorbed). Absorbed CO ₂ is held firmly within the concrete and will not escape into the atmosphere.

Nendo designed concrete walls that resemble screens. About 2,050 concrete blocks are arranged in many rows to form 5 3m high walls. The construction team adjusted the angle of the blocks to control visibility. Depending on how the blocks are arranged, they control what is visible and what needs to be hidden, ensuring ventilation and also privacy.

_{Nendo uses carbon-absorbing concrete in construction to help reduce CO 2} emissions in the world. According to a study published in ResearchGate in 2023, the world's cement and concrete production produces about 8% of total carbon emissions. CO ₂ emissions from energy used in the cement industry in 2020 accounted for about 1.2% of Japan's total emissions.