Sompasaari Housing

Background: site allocated competition 2015
Type: building and courtyard design
Client: Lapti Ltd, City of Helsinki (courtyard)
Status: completed
Timeline: 2015–2021
Location: Sompasaari, Helsinki, Finland
Scope of project: 14 200 m² housing (247 apartments), 300 m² commercial
Team: Antti Lehto (partner in charge), Emilia Ellilä (project architect), Leena Buller (landscape arch. in charge), Kristina Östman, Anna-Kaisa Aalto, Anni-Mari Anttola, Timo Arjanko, Lassi Luotonen, Timo Paananen, Daniel Reini, Antonino Vitale
Photography: Mika Huisman, Martin Sommerschield (Kuvio Ltd), Daniel Reini (INARO), Tuomas Uusheimo


The site lies in the redeveloped East Harbour area of Helsinki. For decades the cityscape has comprised rough industrial buildings, warehouses and chimney stacks.


The architecture has its roots in the history of the site. Simple volumes, a variation in scale and rough brick work provide an industrial touch.

New typological combinations

Various apartment types coexist in the block to meet the requirements of various lifestyles, thus enriching the townscape and enhancing social diversity. The logic of representing apartment types in the façade creates the logic for the architectonic expression.

The innovative combination of circulation spaces and floor plan types opens up new prospects for variation in unit height, size and views.

In the owner-occupied apartments towards the sea, an openable glazing protects the balcony from harsh sea winds. The extruding parts of the balcony brings life to the streetscape through the visibility of small personal items such as flower pots and furniture.

The idea behind the varying balcony width is to create spaces for furniture both in the interior and exterior. The narrow parts of the balconies enable direct access from the sea-side rooms.


An unique feature in an apartment building is the possibility to relax in outdoors while having a sauna, part of the Finnish sauna culture.

In the rental apartments, a well-lit vertical space connects visually floors, while the glazed outdoor corridor provides access to the lower volume beside it. Limited in length, the outdoor access serves only three apartments per floor, fostering a sense of community on each floor.

Integrated design

Our landscape architects designed the courtyard in close collaboration with the architecture team. The soft volumes and smooth transitions create a contrast with the clear-cut building volumes. Despite the relatively high building density, residents can find sunny locations in the multi-purpose green area, surrounded by the public access route.

Careful brickwork

The contrast of scales in the massing of each building, variation in brick cladding and careful attention to detail bring a sensitivity to the design that counterbalances its rational approach.

Storage of renewable energy

Rooftop solar panels are connected to a battery-charging station. Charging and usage are optimized according to available sunlight and consumption demand.

The Diana block in Sompasaari represents a clever combination of scales and housing typologies.