Researchers from Aalto University and the Finnish Environmental Institute studied how creating buildings with wood would change the construction industry’s carbon footprint and developed a model that could be used as a roadmap to increase wooden construction in Europe.

While buildings create one-third of global greenhouse gas emissions, the team found that if 80% of new residential buildings in Europe were made of wood, and wood was used in structures, cladding, surfaces and house furnishings, buildings could store 55 million tons of carbon dioxide per year. This is around 47% of the European cement industry's annual emissions.

The Aikalava pavillion was built to celebrate Finland's 100th birthday. Source: Vesa Loikas

The team looked at 50 case studies and divided the analyzed buildings into three groups according to the amount of wood used and how much carbon dioxide they store. The group with the least amount of wood stored 100 kg of carbon dioxide per square meter, the middle group stored 200 kg of carbon dioxide and the largest group could store 300 kg.

Potential carbon storage capacity is based on the amount of wood used as building components. The team also looked at how Europe could achieve a significant CO2 cut by modeling a path to reach CO2 levels of 55 million tons per year by 2040. For example, if 10% of new residential buildings built in 2020 were made of wood, they could store 100 CO2 kg m2. Wood-built buildings would need to grow to 80% by 2040 to reach carbon storage goals. This scenario demands a shift to wooden buildings that store more carbon dioxide.

Energy efficiency is frequently used to measure the environmental impact of buildings. Energy efficiency requires more insulation, efficient recovery of heat and better windows. Half of the carbon footprint of zero-energy houses occurs before anyone has even started living in them. When energy used in housing comes from renewable sources, the significance of the construction phase of the building’s total environmental impact grows.

The team notes that wood construction is only sustainable if the wood is coming from forests that are sustainably grown.

This study was published in Environmental Research Letters.