Small plots challenge architects – we took on that challenge, and here is the result:
Haus cj_5 – housing in urban density
With Haus “cj_5”, Caramel addresses the question of sustainable densification of Vienna's urban fringes.
The building class prevailing there, with permitted heights of 4.5 to 7.5 metres, allows two-storey detached or terraced houses which, with their gardens and terraces at living level, offer a high individual quality of life, but whose low usable floor-area density (UFD = residential floor area / site area) of 0.2 to 0.4 consumes a great deal of land.
From an infrastructural and space-saving point of view, these areas should aim not just for dense low-rise housing (UFD 0.4–0.8) but for a UFD of 0.8 to 1.2, which is currently only achieved with dense multi-storey apartment blocks.
The pilot project Haus “cj_5” by Caramel Architekten achieves a UFD of 1.0 while keeping the qualities of a single-family house, with a generous garden and terrace at living level – making it as dense as a multi-storey block of several flats without direct access to outdoor space > see the graphic “site plan and usable floor-area density”
This is made possible by a narrow 5 x 35 m plan with fire walls on three sides allowing direct adjoining construction, internal linking of the living levels, a central atrium garden and focused horizontal and vertical daylight openings.
From outside you enter a relatively closed white spatial sculpture, which then opens up further and further via the studio / garage forecourt to the living area and atrium garden, so that despite the narrow plot it develops very generous, interwoven spaces inside.
The outer white cube continues as an inner white cube in the studio / garage and the cinema in the basement. In the living and office area behind, continuous exposed concrete surfaces with a board-formed finish on walls and ceiling, and continuous wooden floors running in the same direction as the board pattern of the walls, join interior and exterior into a spatial continuum. It slides over the central kitchen platforms as part of the stair landscape (cj_5 = cooking jockey, 5 m wide) over the studio to the sleeping area upstairs. The adjoining bathroom and WC are each designed as separate colour islands with very small tiles. Thanks to the “room within a room” system, all living and office areas have visual connections with each other and with the central outdoor space, the garden atrium.
The house draws its energy almost self-sufficiently from photovoltaic panels on the south-facing roof surfaces and an air-to-water heat pump, and in terms of insulation is designed as a low-energy house (heating demand 41 kWh/m²/a).
