5+1AA (now Atelier(s) Alfonso Femia) Architects: Simonetta Cenci, Alfonso Femia, Gianluca Peluffo
Inside the WhaleThe Piranesi Experience is producing an unpublished cinematographic story of the new headquarters for the BNL Paribas in Rome.
After the first scenes, which seem to amplify the majesty of the architectonic mass, we slowly enter the belly of the building, which due to its form, brings to mind the spotted whale.
The camera then turns outwardly towards the inconsistency of the curtain wall, which enhances the scenic potential of the facade, rendering it a reflective and changeable stage scene with the passing of hours, seasons and climatic conditions, never appearing equal to itself.
The double-side douter wall, with its differing inclination of the slanting plane – which is fragmented into a regular sequence of recesses and projections– amplifies the changing effect of the front towards the railway, making the view dynamic. Such dynamism is lost from the opposite view, the one facing the northwest, more static and material, called to encounter a “slower” urban context, represented by the Pietralata district.
Populus' pressing soundtrack articulates the footage, which follows a continuous pursuit of light and surface, generating optical illusion effects and kaleidoscopic visions, captured by the story created under the direction of Claudio Esposito and with the photography of Fabio Paolucci.
The reference is to the work of Daniel Buren with the reflection and refraction effect produced by the glass and diamond-like ceramic facade panels that in a continuous metamorphic process intercept changes within the surrounding reality.
Sunset has arrived. The rays of the sun directly hit the building, which absorbs them, reflects them, and begins to glow. The footage is now more static, the border between sky and architecture becomes transitory, the facade vanishes and is camouflaged within the context.
Rossana Vinci, architect and journalist
The plan has a longitudinal layout on the small, narrow area. The classic back-front idea was discarded in favour of a dynamic composition that slants down from the highest to the narrowest point, with the ability to “modify itself” depending on the incidence of sun rays during the day. The main feature of this building, which is developed on two façade planes (one linear and one that acts on the deformation of the plane itself), is dematerialisation.
A shimmering façade acts on the break elements. This effect (which is difficult to obtain) is the result of a major architectural study that took into account all the geometrical and landscape elements, combined with the many restrictions the project had to comply with (e.g. the presence of the historical Mazzoni water tank). Planning restrictions imposed by the Code of Cultural Heritage apply to the Mazzoni water tank, which stands in the area. This meant that a large window with a view of the water tank was created in the part of the building by it. Here there are no pillars and the building is suspended by a covering “bridge” concealed by the façades.
Near the southern end, the plan of the building tapers following the perimeter of the plot. It also tapers heightwise, so the last three bays have different heights, which provides room for access and for escape routes. The major cantilever is made of steel truss in the façade planes and in the floors, which is the effect of the markedly spatial nature caused by the structure’s asymmetry.
The very narrow plot and the direct relation with the Tiburtina train station have essentially led to development along a linear dimension. The result is a building that is 18 meters wide and double that at the end of the block, where the plot permitted it. This choice has made the building light (like a tower) and created a dialogue with the landscape restrictions - never a clash.
As the architects themselves said, the building complies with a “collective architecture” idea, in which the areas for interaction and sharing among people and between individuals and landscape create the public function of the project itself.
A more detailed analysis of the outer covers immediately reveals that the building’s glass façade is a unitized facade, with a customized system.
The self-supporting panels assembled and structurally glazed hang from brackets anchored to the floors, to compensate floor deflections downwards as well as thermal movements sidewards.
The panels are fabricated with specially designed extruded aluminium profiles and come with gaskets and accessories (doors, operable windows, sealed windows). The enclosing walls are double glazed glass of various kinds (vision, spandrel), with the shadow box at the belt courses.
The façade is anchored to the building’s load-bearing main structure by aluminium/steel brackets of different shapes that allow adjustments for construction and assembly tolerance and for the possible relative movements of the building.
In typical cases the brackets are anchored to the concrete slabs with the cast in channel system of Locatelli profiles or, if these are not in the plan, a chemical anchor system from Hilti is used.
In certain areas of the building there is a small multifaceted bed between the vertical cells which, on alternate sides (inside/outside), acts as a joint between the various “cusps” included in the architectural design.
The two sides of the project
On the western a unitized façade was used, where as on the opposite side the focus was on creating a “Bow Windows” system, using ceramic for aesthetics and ventilated façades for function purposes. The mullion and transom system was used to build the ventilated façades.
Shading systems and shades have been deliberately left out of this project. On the Western side, the 230 metre main front has a 15,000 square metre continuous glass unitized façade. To satisfy this incredibly long building front, with sections of different heights, a system of thermal break aluminium and double glazed IGU was used. The 10 mm thick glass layers are paired and separated from each other by a weather sealant joint (designed to prevent water, air and wind leckage). The external (tempered monolithic) selective coated glass has high levels of light reflection and the façade's overall thermal transmittance (Ucw) is very interesting indeed.
There is a 10,000 square metre ventilated curtain wall façade on the eastern side of the building. There are various sections - a façade without thermal insulation in the cold supply areas, a façade thermally insulated in the hot supply areas, thermal insulated reinforced concrete cores inside the offices. Bevelled-edge tiles (30x60cm) with a three-dimensional shape compensate for the movement of the upper side of the façade with an external finish, which is an interesting element for the dynamics of the entire building. These special tiles are laid out in modules made of two elements each and distributed lengthwise, in order to maintain the “movement” theme.
Transparency on one side, kinetics on the other - here is the double face of the new BNL premises in Rome.
Commissioning body: BNP Paribas Real Estate Property Development spa
Tenant: BNL, BNP Paribas Group
Final architectural design, coordination and Supervision of works: Starching
Structural working drawings: Mauro E. Giuliani, Engineer, Redesco Progetti srl
ME engineering project: Ariatta Ingegneria dei Sistemi srl
General contractor: PGC Parsitalia General Contractor