Atrain is located in Verkkosaari, a former industrial port area in Helsinki. This visually unified residential block is divided into five sites and three different housing ownership companies. One of which is Hitas owner-occupied housing, the second is Heka right-of-occupancy housing, and the third is Ara rental housing.
Names like Verkkosaari (net island) and Kalasatama (fish port) have played a big part in remembering the seagoing history of the area. A Helsinki tradition from the 19th century, to give city blocks individual names, has been revived in Kalasatama, and the block of this project is called Atrain (a trident). The office has completed several other projects also in the nearby area; each with names referencing the sea; for example, there is an owner-occupied co-housing project named Sintti (a minnow, a little fish), which is the smallest building in a block named Viehe (a fishing lure). Another similar housing project is under development named Ankkuri (anchor). Two senior co-housing projects have also been completed; Kotisatama (home port) and Loppukiri (the last spurt).
Following the town plan design by Lahdelma & Mahlamäki Architects, the residential buildings are designed as seven-storey point blocks to allow for more light to enter the courtyard, as a way to combat the overshadowing of the nearby shopping centre’s tall towers.
Residents' common spaces are mainly on the top floors. The point blocks are connected together on the lower floors and there are some further commons spaces also in these lower-level joints. The ventilation plant rooms are hidden under the pitched roofs tilted towards the courtyard.
The demands of the town plan also enabled exceptionally varied views and space solutions. The orientation of the floorplans was due to the town plan forbidding the placement of emergency escape routes in the courtyard. All apartments are oriented towards the street and have a street-facing balcony. The colourful balconies of the lower apartments highlight the street-level arcade.
Budgeting led to the size of the underground car park being reduced, by swapping individually reserved car spots for shared-use car parks and shared-use electric cars. This solution had a positive result by creating more space for an earth-bound courtyard including space for large trees, an exception in the Kalasatama area.
The facades on the street side are light-toned brickwork in accordance with the town plan. Also, following the plan, the courtyard facades are built uniformly and constructed of panels matching the height of the levels, in this case using solid-coloured concrete sandwich panels. The surface of the panels features two different textures; smooth formwork and rough exposed aggregate. The panels form vertical, level-high stripes, where the appearance of the panels is faded by placing the horizontal joins of the panels on the upper edge of the window frames and vertical joins on the edges of the textured fields. The varnish colours, provide necessary surface protection and vary for each building, giving each its own character.