The tower emerges from the ground, tapers at the centre and finally opens itself to the sky, with a light and transparent bridge volume on its top linking the two wings. The perforated outer skin has a sand-like colour and envelopes the structure like a vegetal bark. A “natural” form, a large tree in the park accommodating and sheltering the housing functions at the ground level.
The 170 m high tower will rise from a cylindrical podium including two above ground levels accommodating public functions (lecture hall and children’s library) plus an underground car park for 36 cars. The building’s top will be occupied by a panoramic deck and a floor accommodating a café.
The building will become part of the park along its main SW-NE axis, with the solid and non glazed sections opposing the prevailing winds that will thus glide on the rounded off profiles, while the glazed sections on top will be open to the city and the sea in the distance. The building will be surrounded by green strips and a paved access area, with three pedestrian ramps plus one for cars emerging from the underground level. Cars will access the building from 6 Street and a meandering road in the park.
At the underground level a circular car park placed out of the projection of tower’s volume above will front on a central landscaped court – light will penetrate and the vertical connections (service stairs and panoramic elevators) will be visible from this opening. The underground level will be accessed from the outside via long pedestrian ramps and from the inside of the floor of the podium above via an elevator and a stair built into the void structure. The outer crown will have large ventilation spaces, two of which will be connected by ducts to the building’s central court.
All the building’s functions will be accessible from the lobby at the ground floor. At the centre an inner court will rise through all the floors (underground, ground and first), bringing light to each of them and accommodating the panoramic elevators and the service stair. This green court, connected to the ventilation ducts at the underground level, will generate an air flow (chimney effect) that will cool the building’s inner skin as well as the inner layer of the façade’s glazed sections, thus reducing the need for air conditioning. Aside from the aesthetic effect, the court’s plants will contribute to the atmosphere humidity and keep temperatures low thus providing a more comfortable micro-climate. This green system will be visible through the façade’s transparent sections. The net floor area at this level is about 450 sq.m.
The first floor will accommodate a children’s library facing both on the outside and on the inner court. The library’s two areas will be connected by a slim glazed bridge overpassing the court on one side, while the void structure will accommodate the technical services and the area of the vertical connections in the podium. The net floor area at this level is about 450 sq.m.
The areas for technical services are accommodated in the tower’s central area, where there is the connection with the tubular structure.
At the tower’s top, visitors will enjoy the surrounding view from an open panoramic deck, while a further level above occupied by a café will shelter them from the sun. The deck’s glazed parapet will give a clear perception of the void below. The deck’s net floor area is about 150 sq.m.
The café at the top floor, at 160 m of height, is a slim and glazed bridge volume connecting the entire structure at the top. At this level, two large glazed holes will allow the view of the arrival of the vertical connections built into the void structure. The café’s tables will be placed along the panoramic walls, built with inner glass wind-braces, while the services will be accommodated in the structure’s void areas. The glazed walls and the floor’s top surface of the café and the panoramic deck will be faced with mirror glass dematerialising the entire volume and the floor of the panoramic deck where, observing the tower from below, one will see the reflection of the sky and part of the underlying structure. The net floor area at this level is about 150 sq.m.
The structural concept is based on two side void tubular elements built in high-strength concrete and connected in the central section and at the top of the tower. The presence of void areas in the tower’s upper section will produce a lighter structure. The leaf-like shape will have a regular development on the inside, while on the outside it will present a alternately slimmer or fuller profile along the tower. These load-bearing elements will also act as horizontal and vertical wind-bracing. The podium and the volume’s top structure will be made of concrete pillars and beams.
The podium and the volume’s top glazed walls will be composed of a double glazed layer with an inner gap of about 50 cm allowing for the natural circulation of air and the possibility of introducing small plants. The air penetrating in this gap will flow out from slits at the base and the top of the walls. The outer glazed layer will function as a wind-barrier as well as a filter to sun radiation and heat. The inner layer of the glazed walls at the podium levels will be openable in order to ensure air renewal. Adjustable brise-soleil shades, connected to photovoltaic cells, will be placed between the outer and inner frames, while the solar radiation will also be deflected by the presence of the small plants between the glazed layers. When the air circulation system is off, the walls will create a sort of greenhouse environment keeping the heat inside the building and reducing the need for heating, while with the air circulation system functioning, an air flow will be generated that will cool the inner layer of the glazed walls, thus reducing the need for air conditioning. The building’s roof and part of the podium to the south will be covered by photovoltaic cells – the same devices used within the glazed brise-soleils on the south walls and on strips of glazed walls. This solution will ensure the efficient production of clean energy due to the absence, in the surrounding area, of obstacles compromising the direct irradiation of the cells.
The living conditions in the interiors will be made more comfortable by the opportunity to adjust temperature and lighting levels as well as by the visual stimulation offered by internal and external views. Being responsive to climatic factors, such a building will also promote the users’ aesthetical well-being, allow for the perception of the climate outside, and integrate the interiors in the daily and seasonal changes thus avoiding the feeling of living the working day trapped into an artificial environment that remains unchanged over the year. Other particular features include small-scale energy savings, for example the opening of a window in a particular room will automatically stop the air conditioning, or sensors that, not detecting the presence of people in a room, will automatically put off the lights. Also, waste water from the cooling system will be reused for the toilet drains.
Perforated by variously sized openings, the outer skin will have a sand-like colour and, in the points where it does not overlap with the tubular load-bearing, it will let the light filter in and create a play of shadows, or give place to the irregular interruption of the view of the surrounding landscape for the visitors ascending to the tower’s top on the panoramic elevators. The character of the skin’s pattern will be further enhanced by the shape of the building that, starting from a circular plan, will develop into a sinuous and rounded-off volume clearly emerging from the urbanscape. The natural light filtering from the outer perforated membrane and the tubular structure, also irregularly perforated in the podium’s side spaces, will create a diffuse and richly contrasted atmosphere. One will pass from the shaded rooms set into the tubular structures to others more brightly lit in the glazed sections or to the view of the inner planted court. Light and its reflections are design elements and as such acquire a crucial role, generating contrasts that evoke the memory of the Islamic city’s dense fabric opening into shaded or planted courts. The dramatic effect will be particularly evident in the evening and at night, when the perforated envelope will let the lights placed between the outer skin and the structure shine through.
