The installation of the first residential building of Wood City in Jätkäsaari, Helsinki, has started. As its name suggests, Wood City is built using mass timber. The wooden multi-storey buildings are made of LVL (Laminated Veneer Lumber) panels manufactured at Stora Enso’s Varkaus mill, Finland.
Developed by SRV and Stora Enso, the compound is a sustainable urban quarter built for the Helsinki municipal housing developer ATT and comprises two residential buildings, an office building, a hotel, and a carpark. The apartments are estimated to be completed in February 2018, while the rest of the development will be completed by the end of 2019.
Rapid construction without weather protection
A distinctive feature of this construction method is that the buildings’ wood frames can be installed without weather protection, a first in Finland.
“Building without weather protection is common in wood construction and well-suited for wood as it is an organic and natural material. The moisture handling for the materials is meticulously designed for the installation process, with all required actions and risk management are planned in advance and approved by Helsinki City Building Control. Furthermore, automatic sensors are installed in the building for measuring moisture throughout the construction process,” said Petri Perttula, head of Building Solutions at Stora Enso.
This method enables a significantly faster assembly time than traditional solutions, in many cases, twice the speed. After the building frame is erected, the roof is sealed in only a few hours. The materials will be ventilated by fresh air running through the openings in the façade. Thus, the building sets itself naturally to the humidity it needs. The interior fitting work can commence very quickly, and the risk of exposing the structure to moisture is mitigated according to a natural process.
The installation time of the first wooden multi-storey building at Wood City is estimated to be less than one week per floor on average. The total time for erecting the LVL building frame is estimated to be less than seven weeks of continuous operation.
Wood City, as its name suggests, will be built in mass timber.
Wooden buildings as a competitive alternative
Wood is a reusable, renewable, sustainable and cost-competitive construction material that has scientifically proven health benefits. Wood has the lowest CO2 emissions amongst building materials and it creates a long-term carbon storage.
“The industrialised processes and innovative concepts of wood construction make wooden buildings a highly competitive and sustainable alternative. We want to raise awareness of how using wood as a construction material is a climate-smart choice and a solution to meet the needs of population growth and urbanisation. Since wood is the only fully renewable building material, it is unbeatable also from an environmental perspective,” said Jari Suominen, head of Wood Products from Stora Enso.