is part of a case study on filling gaps in the city with optimised, customisable townhouses. Townhouse A.S. is 5 metres wide and has an inner width of 4.2 metres. The plan layout follows a 600 x 600 mm grid. The staircase is a crucial component for this type of dwelling, and it needs to be functional, comfortable and artistically appealing. This design solution connects the entrance with the kitchen through a sculptural ceiling structure. The kitchen connects to the living room by a wide stair part of the building’s everyday activity. The main challenge on such a limited plot is to arrange the common areas of the house. The living room is placed on top of the entrance area, enabling direct communication between the building’s common spaces.