Construction work gets underway on Helsinki’s Wood City

20 January 2017

The first residential building of Wood City in Jätkäsaari, Helsinki, has got underway and will be a powerful testament to the capabilities of timber as a construction material.

Wood City is intended to become a sustainable urban quarter built for the Helsinki municipal housing developer ATT and comprises two residential buildings, an office building, a hotel, and a parking house.

The residential buildings are estimated to be ready in February 2018, and according to current plans, the whole of Wood City will be completed by the end of 2019. Wood City is developed by SRV and Stora Enso in cooperation.

The wooden multi-storey buildings of Wood City will be built using a technology based on LVL (Laminated Veneer Lumber) panels manufactured at Stora Enso’s Varkaus mill, Finland. New, innovative building solutions have allowed massive wood to enter into new construction end-uses traditionally dominated by concrete and steel.

The massive wood construction method applied in Wood City is a widely used best practice across Europe, says Stora Enso. A distinctive feature of this method is that the massive wood frame of the buildings can be installed without weather protection. In Finland however, it will be the first time this method is used for multi-storey, massive wood buildings.

“Building without weather protection is a very commonly used method in wood construction and is well-suited for wood being an organic and natural material,” says Petri Perttula, Head of Building Solutions at Stora Enso. “It is crucial to note that moisture handling for materials is meticulously designed for the installation process. All required actions and risk management are planned in detail in advance including the moisture handling plan approved by Helsinki City Building Control. Furthermore, automatic sensors are installed in the building for measuring moisture throughout the construction process.”

Rapid construction time of the primary structure is one of the major benefits of using massive wood elements. This method enables a significantly faster assembly than traditional solutions; in many cases double 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.

“The industrialised processes and innovative concepts of wood construction make wooden buildings a highly competitive and sustainable alternative,” says Jari Suominen, head of wood products at Stora Enso.

“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.”