When Castellum created its new regional office in Örebro, employee needs were at the center. One early challenge was the problematic sound environment, and Castellum contacted Zilenzio to find a solution that could create a calmer and more functional workplace. As one of the largest commercial property companies in the Nordics, the ambition was to create an attractive environment that supports both employees and the business.
“We are a very diverse company with many different roles, but it still needs to be an office that works for everyone. That is why we did extensive preparatory work, using reference groups across all roles to understand what our specific needs were as a business. Everyone has had the opportunity to influence the outcome,” says Sofie Lundberg, Business Developer at Castellum.
As a publicly listed company, Castellum is a driving force in creating attractive offices and knows what it takes for employees to want to come into the office. The new office was therefore also designed to function as an inspiring showroom, demonstrating how sound, light, and the overall environment can work together.
From a problematic to a pleasant sound environment
The previous tenant had already warned Castellum that the sound environment in the premises was poor.
“They were sitting in an open-plan office and the sound bounced into the front part of the space. Overall, it was very messy acoustically,” says Sofie.
Sofie contacted Linus at Zilenzio early on for support. After the first meeting, they had many ideas on how the sound environment could be improved. This was followed by acoustic calculations from Zilenzio, who also developed a solution with table screens, wall absorbers, and floor screens with plants to create an office that is both functional and visually appealing.
“We have ended up with something incredibly beautiful. The spaces feel very welcoming and homelike, with grounded, tactile materials. We think it has become a very, very good work environment,” says Sofie.
The sound that previously bounced around is now gone, and employees have gained a calm work environment, not only in the office areas but also in smaller meeting rooms and conference rooms. The most noticeable effect, however, was at the desks. With new table screens that both absorb sound and create greater privacy, the entire layout changed.
“We did not think it would have such a big impact. But the fact that they are more sound-absorbing and a bit higher made us go from sitting in groups of four to feeling more like sitting two by two. The landscape became much calmer and you feel more sheltered. It has really contributed to a different feeling in the office,” says Sofie.
How to create an office where employees thrive
A common challenge when companies develop their office or move to new premises is that they continue with the same solution as before, despite new conditions. Sofie recommends that companies first identify what they want and what they actually need.
“Go back to the core of what the employees or the business need. Based on that, you decide whether to stay in a space or move, and then make adaptations accordingly. Not everyone thrives in an open-plan office. Some may prefer a more activity-based setup with flexible and varied spaces for different types of work, so you are not always sitting in the same place that may not support both focused work and collaboration,” says Sofie.
A large focus on reuse
Sustainability was another key part of the project. Castellum reused large parts of the existing interior. Rooms were dismantled, partitions and glass doors were relocated, and a floor was moved from one room to another. Existing lighting tracks were kept, and 50 percent of the furniture was reused.
“The climate impact here is actually relatively small, considering how much we have been able to preserve or reuse. It is really rewarding to see the numbers, to measure them, and to make this a major focus, which it truly is for us at Castellum,” Sofie concludes.
The new office also gained external recognition and was nominated for Sweden’s Most Stylish Office 2025. Even though it did not win, the result is clear. Castellum has created a workplace where employees thrive and feel well, with a sound environment that supports both focus and collaboration.
