Wood City – Supercell’s office building


Two residential apartment buildings (phase 1) and an office building (phase 2) have been completed in Wood City, with a hotel still planned to come (phase 3). All the buildings are eight storeys tall. The buildings in the complex will also share a three storey car park (part of phase 2) and courtyard.

The new building completed in Wood City includes an eight-storey wood office building and a three storey car park with 170 parking spaces. The office building serves as Supercell’s new headquarters. Concrete was used for the office building’s ground floor, the basement and the elevator shaft/stairwells, while wood was used for storeys 2 through 8. The laminated veneer lumber (LVL) is from Stora Enso’s facility in Varkaus, with the wood mostly coming from private forest owners in the surrounding region of Savo. The CLT came from a Stora Enso facility in Sweden, with the wood mainly coming from Stora Enso’s own forests in the area.

Supercell’s headquarters is the largest wood office building in Finland as measured by the amount of wood used. This qualifies as an eco-action, as this amount of wood binds the CO2 equivalent of a year’s driving for 600 passenger cars.

The gaming company Supercell Oy moved to the office building in Wood City with the aim of creating the world’s best work environment for its employees. This rather ambitious goal was broken down into the following targets:

  • First-class quality
  • Superior surroundings
  • Flexible configuration

The design solutions focused on creating superior surroundings. Examples include air conditioning, careful material choices, and first-class acoustics that include a sound masking system. The flexible space configuration takes user needs into account. The resulting solution also facilitates the reconfiguration of office spaces for future needs.

Construction project

From the very beginning, the project sought to engage employees and to promote transparency and teamwork. The aim was to consciously facilitate the Supercell mindset where teams openly share knowledge and lessons with each other. The project team included people from the SRV project and site management group as well as representatives from Supercell and the HTJ construction consulting services hired by Supercell. The team wanted to do things right and according to a properly managed plan, but they also wanted to challenge the traditional ways of doing things.

Although this was a turnkey project, the approach included collaborative methods. The site is testimony to the fact that collaboration does not always require alliances.

As the project progressed to the construction phase, the client was very much part of the process. The project sought ways to challenge traditional ways of working and to make the client’s corporate culture part of the construction site processes. This turned out to be an important operating model because a lot of changes and even completely new systems came up during construction. Changes in the team space layouts in December 2018 were the single biggest change. This totally transformed all the interior structures and the systems the users wanted, all while the concrete framework was already being poured.

The subcontractors were brought together in Last Planner sessions twice a week, which allowed them to coordinate their work for the upcoming phases. Last Planner sessions are an important tool for managing changes during construction. They allow everyone to react quickly to changes and to share information effectively with all the contractors. The subcontractors showed an excellent level of participation and were eager to commit to the shared goals of the project.

Quality walks and gates

One of the important keys to success was the level of quality Supercell wanted. The project team knew from the start that this site that would require more scale models on site than usual. To support the design work and to test the user experience, a 1:1 scale model of a team space was created for the project. This made it possible to test different technical, structural and surface material options.

The project team recognized that the best way to reach superior quality standards was to get everyone to commit themselves to the goal and to work together to get the best possible outcome. Strong collaboration was key.  Contractor and/or building component specific quality walks and gates were used to encourage quality workmanship and to highlight the importance of the required quality. On quality walks, the project team inspected building components or end results on-site together with suppliers/subcontractors. It was beneficial to have Supercell available on-site as it meant workers were able to receive feedback from the actual end user.

A stocking-foot construction site office and a grill for the workers

From the start, the concept of a good working environment was extended to include everyone at the construction site. While the site office was a traditional office trailer often seen on construction sites, the interior was made more pleasant with light-coloured paint, some greenery, a free coffee machine, and adjustable desks for all who wanted them. Wall-to-wall carpeting was installed in the office, creating SRV’s first-ever stocking-foot site office.

The shared goal was to make the working conditions so pleasant that trained workers would not want to switch to another site. To further this goal, a management team for workers with one representative (not a foreman) from each subcontractor was created at the beginning of the project. This team met for lunch with SRV and Supercell project management once a month. Over lunch, the team discussed working conditions and development areas in a free-form manner. The intention was also to inspire the participants to challenge traditional operating models. This model provided valuable, “unfiltered” information on site conditions, which was then used to improve working practices. A grill area was also set up on the site, which made workers feel more comfortable and helped maintain the social distancing required in the Corona era. Workers also had common lunch breaks where Supercall offered lunch for the entire site. This made it easy to share news and gave people a sense of team spirit.

Zero accidents

Occupational safety received special attention right from the project’s planning stage. As there was very little room to maneuver on the site, careful planning was required to ensure safety not only on the site itself but also for other operators nearby. The accident rate for SRV on the site was zero. The average for the entire site was 17.88, which can be considered to be a good result considering the 1.9 million hours worked. The site particularly excelled in making safety observations. A total of 1,278 observations were made in 2019, which is the highest across all SRV construction sites. Safety gates were conducted once a week by SRV’s management.

Successful moisture management

For moisture management, the project team worked with leading experts to develop a detailed moisture management plan for the construction phase. This plan was followed meticulously. The core principle of moisture management is that concrete and wood framework structures can be exposed to rain or humidity in a controlled manner when favourable conditions are provided for these structures to dry off after they get wet. The structures then begin to dry according to their natural moisture retention behaviour. The intermediate floor elements were sealed, the edges were dammed up, and rainwater was directed down from the top vault via rainwater channels. When the frame was put up, critical wood frame materials (façade elements, load-bearing LVL elements) were stored with their moisture-sensitive parts protected. Façade installation work overlapped with the installation of the frames. In other words, a façade was installed for each floor as soon as the floor above it was completed.

The moisture management plan was followed closely. As part of their initial training, every employee on site went through a separate moisture management session to ensure they understood the basics and importance of moisture management. Separate moisture management rounds were conducted weekly, and the results were reported directly to the Helsinki Building Inspectorate. Handling moisture management was of paramount importance, and its success was critical to the entire project. Extensive advance planning and collaboration were key. The Building Inspectorate’s feedback has been excellent on this issue.

Significant interest drawn from around the world

Wood City is a unique ensemble, even on a global scale. The site has stirred up significant interest, with delegations from dozens of countries around the world coming to visit. The YouTube channel B1M, which is extremely popular worldwide and has 1.64 million subscribers, also wanted to created a video about wood construction, specifically featuring Wood City. The video was released on the channel on September 9, 2020 (https://youtu.be/L4QYkEpw9pA). In just a week, the video already had had almost 700,000 views and 23,000 likes.

A view to Jätkäsaari. Wood City in the front. Picture: SRV

Number of employees

More than 900 people from about 300 different companies received introductory training for the site.

The average number of people working on the site was 113, with the highest being 225 people.

About 475,000 person-hours were done on the site, which corresponds to about 235 person-years.

Occupational safety

The occupational safety level during construction has been good.

The average “TR” (abbreviated from the Finnish words meaning “residential construction”) measurement used as metric for occupational safety in Finland was 94.2%.

2850 safety observations at the site (The most observations at an SRV site in 2019)

There were no accidents that led to permanent injuries.

Environmental friendliness

LEED Platinum

48 parking spots for electric cars

240 m2 of solar panels

CO2 emissions of the building frame 30%less compared to a control (concrete) site (LCA calculation using a service life of 60 years).

Text: Mia Heiskanen, Commia Communications Agency and Heidi Tetteh SRV
Photos: SRV