Ciro Mariani is the Chief Architect for Expo Milano 2015

Ciro MarianiImportant matters were touched upon and explored in the meeting with Architect Mariani, in particular, the Expo Masterplan, its significance and developments; the added value of the Expo projects and the role of steel in the appearance of this Universal Exposition hosted by Italy; the challenge of ease of dismantling, recyclability and sustainability facing every country in the design and construction of their Pavilions and the solutions found in steel in order to meet these requirements; finally, the approach of young architects to the world of steel.

Universal expositions are global events that offer architecture the opportunity to experiment and present innovative technological and designs solutions.  What is the added value of architecture for Expo 2015?
Contemporary architecture, if faced with the issue of impermanence, necessarily directs the search towards constructive, technological solutions and the use of various, different materials up to the limit of their possible use, sometimes testing the very sense of inhabiting a space, the public space in our case. In this Universal Exposition, perhaps for the first time, the architectural expression shifts its role from matter of construction  - although clear and recognisable, in addition to being extraordinary in certain cases – to the capacity to participate in and translate a theme, to engage and surprise the public, to contain the tradition formal and technological emphasis, often the outcome of these major events, within a common, shared and strictly topical vocabulary:  “Feeding the Planet, Energy for Live”. The added value is the search for and use of native materials, local imports, regional or national interest in a constant balance of know-how. We can go on to define this architecture as “glocal”, a reasonably well-known term, but the uncertainty of our times (perhaps fortunately for us) tends to come up with buzzwords that are, in my opinion, simplifications that do not take account of the fact that the complexity in play is so complicated and the relations so diffuse that to describe the architecture in Milan for Expo 2015 means to reconstruct and present a possible "tradition", export it, unfold it on the site, applying artisan construction techniques with sustainable technological solutions, recyclable, reused and recovered materials, future donations of materials, works, part vegetable and botanical, in a unique mixture of tradition and modernity. It is sometimes sophisticated research of “poor” materials (bamboo, natural earth, wood) applied in a technical and architectural language of subtle and skilful composition of the parts, with the cohesion of different materials such as, for example, what happened with the project for the Chinese pavilion (by the studio Link-Arc, LCC of NY), whose use of traditional and latest generation materials will offer a product with an extremely appealing final result, leaving the visitor with a decidedly direct expression of the issues in defining the relationship between tradition, contemporaneity and future developments; indeed, the wooden structure of the pavilion’s roof revives the traditional Chinese “raised-beam” system, adapting it to modern construction technologies, cladding it with shingle roof of bamboo panels.   Steel is the load-bearing skeleton of the whole building (the primary structural system) with standard European profiles and in some sectors the structures were constructed in AESS (architecturally exposed structural steel); another interesting case is Japan's pavilion, an attempt to give "a contemporary and technically advanced interpretation of the foundations of traditional Japanese culture, close to nature and the life cycle of things"; a steel structure with external non-structural cladding in cedar wood acting as a sunshade, confirming the Japanese tradition of the grid composition.  In the case of the USA pavilion (Biber Architects Studio, NY), the structural steel is entirely recyclable, as are the Xlam panels, the glass and the perforated corrugated steel used for the cladding; as is the “boardwalk” created in wood recovered from the famous, century-old boardwalk of Coney Island in NY. Steel supports and is revealed inside or expresses the same architectural idea without superstructures. Here too, it is sufficient to see the relationship between the pavilion of Vanke by D. Libeskind and the deliberate, measured attention that Spain’s pavilion (Fermin Vazquez studio b720) introduces in the dichotomy between wood and steel, in the use of reflective stainless steel, glued on OSB boards and fixed mechanically on the wooden structure: steel is synonymous with innovation combined with the Spanish food industry; or Argentina’s pavilion that interprets in the light of "impermanence" the steel grain silos scattered over the vast lands of the country. It is impossible not to notice Chile's pavilion by Cristian Undurraga, which uses pine wood (imported directly from Chile) in a skilful and apparent play on structural volumes in which stainless steel fixes, embeds and completes the structural core, almost entirely obscuring its presence but really a determining factor for the final act.

Ease of dismantling and recyclability, sustainability, access for the disabled, green open spaces, these are the specifications imposed by Expo for the construction of all the pavilions of the Universal Exposition. How have countries tackled this challenge?
These are all determining factors in sharing and developing the theme of the Expo at all levels. Following precise instructions contained in the Guidelines for the Design of the Pavilions, all the countries interpreted the theme of permeability and accessibility – “Design for All” – with the greatest care, not only meeting national and local regulations, but accepting as the higher principle that the visitor experience must not have particular physical limits, on the contrary, every project and construction will have to ensure the maximum “comfort” and assistance, including for those who have difficulties of various kinds.
We have always asked participants to pay specific attention, not so much in dividing the able-bodied from those who have difficulties with movement or sight, but to incorporate and consider, with the necessary technical means, the various physical differences (perceptual, sensory, motor, hearing and sight etc.). An attempt has been made to get rid of the notion of "dedicated spaces", replacing it with "spaces for all” in the real awareness that diversity requires clear demonstrations of integration, not only social but also spatial.  It is not limited to defining a route, but experiencing a place. This objective cannot be taken for granted, considering the very great difference in the way each country tackles the theme and that not enough attention is always paid by the designer who should knowingly explore and broaden the principle but not impose a way of inhabiting the space (that is, without segregated areas of clear, dedicate routes that are sometimes, however, marginal).

In your professional experience, what are the advantages in using steel for temporary structures like those of Expo?
Various materials have been shown to be adaptable, with various degrees of technical, functional and aesthetic responses to the principles of impermanence.
Steel is certainly one of the main ingredients and the reasons can easily be understood: structural skeleton, “dry” construction – with a big advantage during the construction phase – the construction of important parts of the project in the workshop, the ease and rapidity of assembly and dismantling, lightness, safety, formal and expressive value, flexibility of use, reuse, recovery and recyclability and more.  The widespread use of steel  is not confined to the temporary works of the pavilions, the Planning Office has designed and built entire pedestrian routes along the canal that borders the site, making full use of Corten and stainless steel, marking the perimeter of the site between landscape and architecture as a place of relaxation, meeting and passage. Every country that has built its own pavilion for Expo has made use of steel, some in virtuous and more meaningful forms, some as a structural element, other in the details and the composition of the fittings, yet others as support for a wide variety of materials and works, as in the case of Vietnam’s pavilion, designed by the excellent young architect Vo Trong Nghia of Ho Chi Minh City, in which steel is used to support a very appealing forest of bamboo. Impermanence has its own characteristic, which makes steel a material of great interest: simplification, that is, the mechanism of artful composition/dismantling.