UNS/Ben van Berkel and Spanish furniture brand Sancal have introduced Gradas, a sofa family that translates the social character of public steps into a flexible interior landscape. Inspired by the informal stair-like seating found in plazas and streets, the collection brings the ease, openness and shared atmosphere of civic space into the workplace, hospitality settings and cultural interiors.

Developed through UNS’s product design service, Gradas reflects the studio’s wider approach to design across scales, from cities and buildings to furniture and objects. The collection began with a single soft prism, a simple geometric element that became the basis for a system of interlocking forms. Combined in different ways, these elements create varied seating arrangements that invite people to perch, recline, gather and interact more freely.

Created in close collaboration with Sancal, the design evolved through hands-on testing of prototypes, materials and colour. This process allowed the stepped form to be refined not only as a visual language, but as a tool for shaping behaviour and encouraging social connection.

As Ben van Berkel, Founder and Principal Architect at UNS, explains: “We spend a lot of time thinking about how buildings activate public life. Gradas applies that same thinking at a very different scale. The stepped form is not decorative; it genuinely changes how people sit together, and that shift in behaviour is what the collection is really about.”

Available in S, M and XL sizes, Gradas supports uses ranging from individual seating to large communal configurations. With varied seat heights, 360-degree openness and a combination of lacquered and textile finishes, the collection is designed to welcome different bodies, ages and ways of sitting. In doing so, Gradas shows how product design can extend architectural thinking into everyday experience. It also underlines how furniture can shape interaction with the same care as architecture.

Find out more about this product here.