Back to Basics? Finland’s Wood City
We sat down to speak with Antti Aaltonen, Business Development Director at SRV. SRV is a Finland-based developer and innovator in the construction industry, it is currently the third-largest construction company by revenue in Finland. Antti was the Project Manager on Helsinki’s innovative Wood City project and offered valuable insights into what makes this project so unique.
In the heart of Helsinki sits a new urban quarter, aptly named Wood City. The development includes two residential buildings, an office building, a hotel and a parking structure, all of which have one thing in common: they are built out of wood. The project has received attention (and numerous awards) for its environmentally minded use of timber as a construction material. However, as we spoke to Antti, it became clear that there was another reason for Wood City’s wide acclaim – its novel approach to working on site.
Our two-part exploration of Wood City will dive into these two key aspects of this project. First, we will outline the city itself and the materials that make it so unique. In the second part, we will share the first-hand experience and expertise of Antti Aaltonen as the Project Manager of Wood City, highlighting the innovative construction processes, particularly the relationships on-site, and how this enhanced the world-class project from the get-go.
What is Wood City?
Concrete contributes 5% to the total annual anthropogenic CO2 emissions worldwide, however, it remains the most widely used construction material in history. In most countries, we live in concrete homes, work in concrete offices and shop in concrete malls. Wood City is challenging this norm by using wood as the building material for almost everything but its foundations.
Even within Finland itself, Wood City is unique. Aaltonen explains that Helsinki was primed for a project like Wood City. Most of the land is owned by the City of Helsinki, which is aiming to decrease its carbon footprint while increasing the amount of affordable housing. Knowing this, “SRV worked with Stora Enso to propose a city that would be a truly hybrid quarter” they envisioned “different kinds of buildings with varying functions in the same quarter. With the housing, the office and the hotel all sharing a courtyard in the middle of the block”. In addition to the hybrid nature of the space, Wood City is home to the tallest wooden building in Helsinki – the Supercell office. Before the project began, regulations passed by the government allowed for buildings to reach up to 8 floors (previously the limit had been 4). Taking this decision in their stride, project teams built the 8-floor office space for the mobile game developer. According to Aaltonen, SRV wanted “to build the best possible office for the Supercell team and I really think we did succeed in building the world’s best working environment for them”.
As of June 2021, though the hotel is awaiting the end of the COVID-19 pandemic to welcome guests, tenants have moved into the apartments, and Supercell has opened its new office.
SRV’s supplier for the project, Stora Enso, specialises in renewable materials. The use of wood was due in part to its comparative environmental advantages over more common materials. Timber is reusable, renewable, and cost-competitive, not to mention the myriad of scientifically proven health benefits it provides. Antti explained that another advantage of using wood in this project was high accessibility levels within Finland. He explained, “Finland has lots of forests. So obviously, log houses have been our choice of buildings since we came out of caves, we have always been building with wood here. Historically it has been much more economic to build with wood compared to concrete or bricks.”
The use of wood in the project is likely to raise some eyebrows in terms of risk. After all, Finland experienced the largest urban fire in the history of the Nordic region, when 75% of the city of Turku was destroyed in less than 24 hours in the 19th century. Luckily, we have come a long way since then. Construction teams utilised a range of high-tech treatments to ensure the highest levels of fire safety across the project. Specially treated wood known as Laminated Veneer Lumber (LVL), which provides higher levels of fire resistance than the traditional wooden beams you might see in many homes, was incorporated into the buildings. LVL’s veneer is layered, making it much less porous than other types of wood. The untreated material is treated in a chemical bath under high pressure, and once the wood is soaked in these chemicals it will release non-flammable gas and water vapour, rather than catching on fire.
Aaltonen also highlights the use of Cross Laminated Timber (CLT) in the construction of Wood City. CLT is known for its extremely high fire-resistant properties, as one sustainability expert put it, “CLT is known as plywood on steroids”. According to Aaltonen, “if you think about the CLT, the fire resistance is actually pretty amazing even without the sprinklers, because of the cross-lamination. Stora Enso actually conducted 2-hour burning tests for their CLT and they lasted for 2 hours without any sprinkler system. So wooden buildings can have that risk mitigated with the use of CLT.”
The Environmental Impact
Some could be wondering at this point, why don’t we just build wooden cities everywhere? Wouldn’t that be much better for the environment? Aaltonen offers an interesting perspective on this issue. He argues that “it is a question about the CO2 footprint overall. It is a matter of how you calculate the impact from the starting point of the materials’ journey”. Of course, Finland is the most heavily forested country in Europe, with 73.4% of the entire land area covered in trees. However, Aaltonen points out that “wood as a construction material is not the sole criteria of the building being environmentally friendly. We should always consider the total impact of the building. So, for us using wood helped with that. But if you have to ship the wood some 20,000 kilometres from the other side of the world, then it might not be the most ecological way of building.”
So, while wood buildings themselves may not be the most globally applicable new-wave in eco-friendly projects, Wood City is an excellent example of how project leaders and planners thought outside of the box to place the environment at the centre of the development.
The second part of our deep dive into Wood City is going to shine a light on other inventive aspects of this project.
Business Writer at Foresight Works