Text description provided by the architects. A typical Tel-Avivian residential building, built in the international style during the 1930's and found in a bad state of the repair was the staring point.
The project included adding an external lift and roof extension to the existing 3 stories structure whilst refurbishing and structurally strengthening the whole building.
The design approach was to integrate the new build with the character of the building, by working with the existing mass and materiality, establishing continuity between elements like the decorative facade cornice and the new lift. The structural work included underpinning the foundations and bracing the building with UPN and flat steel profiles which were mostly concealed in the new render applied to the building.
The roof extension consists of a full extra floor and a partial floor above that, constituting one residential duplex unit.
The flat was envisaged as series of large lit interconnected rooms. Light coming in from the south facing windows on the top level is filtered down through a floor opening and a perforated steel staircase, connecting the two levels. The area left between these two structural holes acts as a "bridge" between the flat and the front roof terrace.
The top roof structure consists of structural HEB beams with a 10 cm layer of concrete cast on top, with the bottom part of the beams perturbing down into the space beneath. This system was chosen in order to maintain a thin continuous roof slab which consists of a horizontal strip that is followed by a steep pitch.
This approach satisfied local building code demanding space for technical equipment on a flat top roof (which was used to install a solar water heating system for the majority of the building) whilst allowing for maximum height inside the space bellow.
The steel beams, clearly visible in the space, continue into the front roof terrace, establishing a strong visual connection and are also used a track system of sorts for internal light fixtures.