Format Elf Architekten has disguised a three-storey family home as a two-storey building by incorporating both upper floors within a large asymmetrically pitched roof.
The pitched roof is the dominant feature of the house, designed to maximise the amount of living space on the limited plot by containing the building's two upper floors.
"The challenge was to keep the free spaces that were required by the public construction authority," studio co-founders Robert Maier and Stefan Hanninger told Dezeen. "The restrictions reduced the available space to one third."
"The roof pitches, which were determined mathematically according to the yard and setback regulations, have been implemented innovatively in the form of an asymmetrical roof in order to create maximum living space on the small plot," they added.
A lounge and study area are both slotted beneath the pitched roof on the uppermost floor, while bedrooms and bathrooms are located on the level below. An open-plan dining area and kitchen occupy the ground floor of the property.
Both recessed and protruding windows puncture the street-facing facade, while larger expanses of glazing were added on the garden side. This allows plenty of light in to the building, but also maintains residents' privacy.
The two rear corners of the house – where the living room and kitchen are positioned – are entirely glazed, while a skylight set into one of the roof's slopes provides additional lighting for the upper-floor lounge.
The house has a timber frame, which facilitated a short construction time of just six months. The underside of the timber floors has been left exposed to create wooden ceilings for rooms on the ground and first floor.
The architects also created furnishings for the 250-square-metre property. Taking their design cues from the house's timber frame, they integrated two black wooden units to separate the living room and kitchen from the stairwell.
Naturally coloured timber was used to create the staircase and further built-in storage spaces.
