Over the centuries, log construction has formed part of the Finnish scenery and mental landscape. Log house production is energy self-sufficient, and even produces added energy, as it generates more energy waste by-product than the energy it takes to manufacture the product. Hirsitaloteollisuus is the Finnish Log House Industry Association and its member companies build 80% of the log houses in Finland.
How it works
Growing trees captures CO2 - a tonne of wood binds 1,8 tonnes of CO2 while growing. But the CO2 may go back to the atmosphere if the trees are cut, decompose or are used for paper or energy. In the case of wooden building elements, the place in the value chain where it makes no economic sense to let the CO2 escape back into the atmosphere is the facility where the logs are cut to measure for a specific building. After this point it would be unwise to use the resulting elements for anything else than creating a long term carbon storage.
In Europe, buildings are regulated to have a minimum lifetime of 50 years, and in real life the CO2 storage is likely to be longer. By storing CO2 for a minimum of 50 years, wooden building elements present an opportunity for companies to invest in carbon capture and storage, and take proactive steps towards carbon net zero.
The wood used by Hirsitalo is sustainably harvested according to Forest Stewardship Council principles. The average (145 m2) Finnish log house stores over 30 000 kg of CO2 and locks it into long-term storage that stays out of circulation for decades.
After the production has been verified for carbon negativity, the extra carbon stored in the wooden building elements is issued CO2 Removal Certificates, CORCs, per each ton of CO2 removed from the atmosphere.
Puro.earth CORCs only quantify the net-removal and storage of emissions, not reduced or avoided emissions, increased biodiversity or other positive benefits. Here are co-benefits self-reported by the removal supplier.
The extra income from Puro is used for member companies’ development initiatives, such as improving the recyclability of log houses. It will also be used to develop tighter collaboration with universities, for example investing more funds in student theses.
1 tonne of log removes 0,4869 tonnes of CO2 eq. from the atmosphere into long-term storage in the product. Life-Cycle Assessment made by Rakennustieto followed the methodology described in ISO 14044 and ISO 14064 standards where applicable.