TOAS Hippos

The design of the Hippos complex started from the goal of providing student housing that would promote a sense of community among its inhabitants. It also needed to complement the surrounding urban structure, particularly the 1950s-era Kaleva neighbourhood. Indeed, the new structure pays homage to the community with its colour scheme, design language, and detailing.

Read the article in Finnish here.

The building’s most striking feature is its street-side façade in white aluminium. The façade curves around the street corner, and its roof line rises and falls smoothly to disguise the variations in height. As the design evolved, the building technology spaces were integrated into the topmost floors, leaving the rooftop intact to further enhance the smooth lines.

Wood-clad walls are visible through large openings in the façade, punctuating the aluminium arch that extends across the entire block. Wood also plays a prominent role in the courtyard, where the cladding is painted in opaque colours that vary from one building to the next. The residential floors of buildings 1B-C and 5E-F, including the apartment balconies, are built with CLT volumetric elements. Wooden surfaces are visible on apartment ceilings wherever fire regulations allow. Varnished wooden window frames further enhance the feeling of living in a wooden house, and the wood surfaces of the CLT staircases have also been left visible as much as possible.

Technical solutions

In the block’s wooden sections, the first two storeys are concrete while the remaining six are built from wooden volumetric elements with beam-based intermediate floors. Element ceilings and load-bearing structures are CLT, as are all elevator shafts and stairwells. Roof trusses are connected with nail plates.

Overall stiffening is based on CLT wall bracing, with horizontal structures distributing loads horizontally. The building is fire class P0(P2) and equipped with a fire detector and automatic extinguishing equipment. Two CLT firewalls, one located between 1B and 1C, split the building’s curved portion into separate fire compartments.

As Hippos is located at a busy intersection, noise presented its own challenges. For this reason, there are no residences on the first two storeys of buildings 1B and C or the first storey in buildings 5E and F. Each apartment has water-circulated underfloor heating and cooling.

Construction

The project began in 2016 with an architectural competition and continued with a call for tenders in 2019. Construction work began with 1B in summer 2022, proceeding to volumetric element installations in 1B in April 2023 and finally extending to 5E in early 2024.

As the project followed an alliance model, designers from different disciplines were able to work in parallel and innovate solutions together. Jointly agreed schedules allowed cooperation to flow smoothly.