Hornsberg 10 is today one of the few remaining undeveloped blocks on Västra Kungsholmen. The block consists of various historical warehouses with varying heights and designs that have undergone several extensive conversions, extensions and additions. It has historically been used for industrial purposes, including a laboratory for Kabi. In the 1980s, an office building was built on the property, called B20.

An overall objective of the project is to develop Hornsberg 10 into a modern coherent block with mixed functions that bring new life to the district during all hours of the day. The ground floor will be made public and accessible with attractive content. New modern workplaces will be added. The block will become a new destination on Kungsholmen!

The property currently consists of buildings B20, B28 and B42. According to the proposal, B28 and B42 will be replaced by a new office volume that in scale connects to B20. In this way, a new coherent city block will be created that relates to northwest Kungsholmen's new block development and the planned development at Hornsbergskvarteren. The new office volume has a public and glazed ground floor with premises, shops and restaurants that are connected to each other through an inner room from which the office floor is also reached. Entrances will be created from Lindhagensgatan, Lars Forssells gata and Nordenflychtsvägen. The existing building, B20, will be opened up and developed with new accessible entrances and windows and a new lower volume around the staff entrance at the corner of Nordenflychtsvägen/Lars Forsells gata. The fan rooms on the roof will be moved down to the basement, reducing the overall height of the building and enabling a new public roof terrace.

The height of the new building varies and connects with the heights of the surrounding blocks and the hierarchy of the streets. The boulevard-like character of Lindhagensgatan is reinforced by returning the block to its main entrance in this location. Inviting places are created around the entrances with prepared paving and seating facilities. Along Lars Forsells gata, the volume is retracted and meets Kv. Leendet's facade life, which creates a smaller place formation with good sunlight. Deliberate lighting and new trees along Lenngrensgatan increase security around the neighborhood.

The starting point for the design is the site's industrial history and the property's potential to become a stately city block on Kungsholmen. The new volumes are built in bricks that are varied, detailed and processed in different ways. The design is based on weight, geometry, proportions and rhythm. The inspiration comes from the older industrial architecture that existed on the site, and which to some extent still exists, for example in the Hornsberg brewery. The design idea is a consistent structure in one and the same material that is allowed to vary and adapt along the different sides of the block. A classic tripartite structure with a double-height plinth floor containing shops/premises, a central section and a roof termination in the form of a penthouse makes the new building land in the stone city. The new building connects to B20 in a studied and careful way with the aim of lifting the whole block to a higher level and creating a new coherent whole.