This extension to the roof of a Brussels apartment block by local studio Notan Office features a fireplace that takes its cues from the work of modernist architect and designer Alvar Aalto.

The project titled Lincoln is a 140-square-metre extension of a penthouse apartment in an residential area of Brussels. Set back from the main building, the extra level is almost invisible from street level.
Two new living areas with floor-to-ceiling windows and terraces that run the length of the front and rear facade flank a central stairwell. The existing top floor has been converted into a private bedroom.

Architect Fre?de?ric Karam worked around the circulation core and two ventilation shafts that were already in situ. Rather than see the existing voids as a hindrance, he embraced them as three of the primary 'cores' or areas of the building. "In order to keep a certain level of rationality, the biggest challenge was the constraint of the lower plan, structurally, constructively, and spatially," Karam told Dezeen.
"It is actually the existing shafts throughout the building that dictated the idea of working with functional cores."

A fireplace wraps one corner of the block containing the stairwell. Formed from concrete and ceramic construction blocks, it lends the apartment an industrial, urban appearance that is tempered by the palette of warm orange and cool greys.
Karam was inspired by the chimneys of Finnish modernist architect and designer Alvar Aalt...