Nuukullak 10 lies perched on the mountain ridge of Entreprenørdalen — a district in Nuuk undergoing transformation from a former industrial area into an attractive new urban district. BIOSIS works from a climate-driven design approach, finding solutions that break down forceful northern winds and optimize the few daylight hours in winter. Studies of wind, flow, and daylight were applied throughout to refine the building's performance and the livability of its residents. The building forms a distinctive horseshoe shape enveloping a truncated triangle-shaped courtyard. The open southern end brings in light and views of the landscape and sea. The courtyard serves as a year-round space for play, communal gathering, and wind-sheltered entry. All entrances and balconies are protected as niches in the building volume. Rock blasting was kept to an absolute minimum to preserve the natural terrain, habitat, and biotopes. The structure follows its natural topography, stepping vertically and horizontally to allow the mountain to subtly influence its profile. 45 apartments range from one-bedroom to four-bedroom. Units feature generous bay windows with views of Ukkusissat mountain and Nuup Kangerlua fjord, and south-east-facing balconies shielded from the prevailing arctic wind. The façade in solid and perforated weathered corten steel interplays with surrounding vegetation, patinating through the seasons in harmony with snow, bedrock, and the nuances of the Arctic landscape.