3XN’s latest completed project in Sweden consists of a renovated multi-story building from 1873 and the construction of a new connected office building. Astoriahuset and Nybrogatan 17 are located side by side in Östermalm, Stockholm’s historic city centre. Focus has been on uniting the existing with the new through form, materiality, and architectural details.

The new Nybrogatan 17 office building connects to the renovated Astoriahuset, located in Stockholm’s historic city district, Östermalm. The surrounding area played a crucial role in the design and choice of materials for the new building, as elements from local buildings were a significant source of inspiration.

Uniting the old with the new
Nybrogatan 17 is designed so that it complements the existing architectural style of the Östermalm district. A unique hand-ironed brick was specially produced for the project and features a darker tone of clay to add a contemporary quality. Furthermore, architectural details of neighbouring historic buildings were reinterpreted as steel ornamentation in the new building.

Astoriahuset’s roof connects seamlessly to Nybrogatan 17 and emphasises the connection between the two buildings. It is a modern interpretation of the classic saddle roof, where the slope runs from a 45-degree angle into a vertical gable, adding a dynamic and distinctive motif to the new building.

“We have put a lot of effort into designing the brick façade, steel ornamentation, and roof’s form to give Nybrogatan 17 an authentic patina and tactility that creates a thoughtful connection to the neighbourhood – and not least to the adjoining Astoriahuset”, says Audun Opdal, Senior Partner at 3XN, who was in charge of the project.

A flexible and future-proof office building
The heart of Nybrogatan 17 is the central atrium and its spiral marble staircase that extends the full height of the building. A glass roof over the atrium ensures that daylight flows into the building, with the staircase helping to create visual transparency, community, and cooperation between people in the building. The sculptural form attracts and encourages people to use the stairs and move around in the building and forms the basis for dialogue and informal meetings.

“We do research in behaviour and work with the philosophy that architecture has a great influence on human behaviour. Our research shows that interaction is much more likely in stairs compared to elevators. Hence, we added more value to the building in creating a holistic and comfortable environment where people can feel that they are a part of something greater”, says Kim Herforth Nielsen, founder and creative director of 3XN.

Creating a flexible office environment that can be adapted to future needs was one of the design team’s main focuses. Nybrogatan 17 offers both traditional office space and inspiring co-working environments that help promote communication and innovation, provide space for different ways of working and opportunities for spontaneous meetings.

Transforming Astoriahuset
Originally built in 1874, Astoriahuset stands directly next to the new Nybrogatan 17. The building, which previously housed offices and a cinema, has undergone a transformation that has brought the building back to its original function – residential apartments.

Today, Astoriahuset contains a restaurant on the ground floor and 18 renovated apartments spread over five floors. The apartments have undergone an extensive but sensitive restoration, with the historical expression being respectfully preserved. The former foyer of the cinema has also been restored and now serves as the entrance of the restaurant.


“We are very proud of the result, where architecture from the late 1800s and new, modern architecture meet in a calm way and open to a square that was not accessible for many years. We have received incredibly positive responses after the opening of Nybrogatan 17 and Astoriahuset, which we see as proof that the high level of ambition has been met”, says Viktor Sandberg, Project Development Manager at Humlegården.

“Urban development and transformation are endless processes, and the key is to make the city’s past connect with its future through form and a coherent architectural identity. The great collaboration between Humlegården and 3XN has been crucial in creating a new building of high quality that blends into the existing urban space”, says Audun Opdal.

Design team:

3XN