For quite some time, residents in the Austrian capital have relied on the ability to extend their townhouses vertically, converting roof space into extra living quarters. The ‘big loft conversion boom’ in the early 1990s represented a new kind of urban renewal and it wasn’t until the end of the decade that regulations were written to prevent a further influx of front-facing roof terraces opening out over the street – a feature typically associated with Mediterranean villas and a far cry from the traditional architectural heritage of Vienna.

The city’s historic centre was inaugurated as a UNESCO World Heritage Site in 2001 and enforced a restriction of roof-space alterations as part of the management plan. Local studio Caramel Architects has added a two-storey extension to an existing house to provide a home for a family of three. ‘Since 2014, new regulations have facilitated the building of smaller and lighter loft conversions,’ the architect explains. ‘The new roofline has to be within a 45-degree-angle imagined extension to the old roofline, so as a pedestrian you’re not able to see the difference to the original structure of the roof from the street.’

The two-bedroom conversion includes everything that would be expected from a modern day apartment, all within the space of an attic. With 72 sq-m of terrace space, the roof-top garden actually makes up 30 percent of the extension’s total floor area and can be reached from every room. The interior layout creates overlapping layers with unusual openings. Unusual design features are incorporated to create a signature environment, such as the white netting – ‘a simple and economical way to protect against falling’ while still encouraging open sightlines – and the steel pipes which are extruded from the chimneys of the apartments below.

Axonometric Diagram

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