Kalasatama is one of the most attractive areas in eastern Helsinki. Construction in the area began in 2009, and today Kalasatama combines housing, jobs, services, and transportation connections into a compact and functional whole. The area is currently home to 11,000 residents, and approximately 13,000 people work at businesses there.
The Kalasatama towers are the largest project in the history of the construction company SRV. Construction of the complex began with the Red shopping center, which was completed in 2018, and in addition to that, five high-rise buildings have been completed so far. In the future, the complex will be expanded with three more towers. Four of the towers are designed for residential use, while the newest one, the Horisontti Tower—scheduled for completion in 2025—is an office building.
Special Characteristics of High-Rise Construction
High-rise construction projects present challenges all their own. Sampo Hirvelä, SRV’s project manager for building services, says two issues stand out above all others. “Special attention must be paid to workplace safety on high-rise construction sites. Much of the work is done while harnessed, which increases the difficulty of the task. Tools, as well as installation and packaging materials, must be securely fastened. Weather conditions must also be taken into account, as wind at high altitudes adds an extra challenge to the work. In the case of towers, cranes were not used when gusts exceeded 10 m/s.”
Another challenge relates to logistics. “Moving goods and people from one place to another plays a major role in these projects, and we need to make it work as efficiently as possible. Elevators play a key role in this task. In addition to construction site elevators, we’ve also used elevators designated for the towers themselves. Some of them were dedicated to logistics, and others to passenger transport. The goal was to minimize the time spent on travel.”
The third challenge is scheduling the work phases. “In tower projects, our goal was to get the building services work underway as early as possible. That’s why temporary protective walls were installed on the vaults before the facades were completed, so that the effects of snow and wind could be neutralized. This allowed us to begin installing the building services as early as the vaulting phase.”
For SRV, building tall structures is routine, and the challenges posed by high-rise projects have not slowed down the progress of the work. “Before Kalasatama, we’ve built other tall structures, such as the Torni Hotel in Tampere. We know how to plan and execute these kinds of projects.”
Horisontti is Finland's tallest office building
The Horisontti office building was the last of the Kalasatama towers to be completed. Construction began in the spring of 2023 and was completed on schedule in April 2025. Horisontti has 26 floors and 11,500 square meters of leasable space. Upon completion, it was the tallest office building in Finland. As a project, Horisontti was also a major employer. “The interior finishing phase is always the busiest part of such projects. Work is carried out in chronological order, and everything must go according to plan so that the next phases can begin on schedule. At its peak, well over 100 people were working on the interior finishing phase each day.”
A large team of professionals was also involved in ensuring fire safety at Horisontti. In addition to PAP Group, SRV’s partners in this part of the project included an electrical engineer, a fire protection engineer, an electrical contractor, and contractors specializing in sprinkler systems, elevators, and automation.
Fire Safety in Order, as Planned and on Schedule
The installation and testing of fire safety systems are always scheduled for the final stages of a project. The fire safety system at Horisont was completed on schedule and without any major surprises. “The project went very well. We didn’t encounter any major challenges during the project, and any minor issues were resolved quickly through collaboration between SRV, the fire safety consultant, the electrical contractor, and PAP.”
A key factor in the smooth progress of the work was that a great deal of attention had already been paid to Horisont’s fire safety solutions during the project’s design phase. “From the very beginning, we wanted to ensure the project’s flexibility in terms of modifications. This contributed to the fact that hardly any changes to the fire protection systems were needed during the installation and commissioning phases. It was a very smart move to devote a significant amount of time to thinking this through back when the project was being designed.”
Verifying the functionality of the fire safety systems installed at the site culminates in the testing phase. “The tests also went really well. We tested the functionality of all fire control systems and conducted a blackout test, which simulated a power outage to verify the systems’ functionality when normal mains power is cut off.”
PAP knew what he was doing
According to Sampo Hirvelä, the collaboration with PAP on the Horisontti Tower project in Kalasatama has gone flawlessly. “PAP has been involved in developing fire safety in Kalasatama ever since the Red shopping center was built. They knew what kinds of fire alarm systems had been installed in the shopping center back then, and they also understood how to integrate them with the towers’ fire safety systems. This was extremely helpful to us during the towers’ design phase.”
The same fire safety requirements apply to high-rise buildings as they do everywhere else. “The most important thing is that the systems operate reliably in all situations. In the Kalasatama towers, everything has worked as it should during testing, and that’s why we’re extremely satisfied with the outcome.”
Article photo: Mikko Ala-Peijari / PhotoCom Oy