Function has been at the heart of 20th century architectural debates. Valued by the CIAM architects, then discredited in favor of notions such as the event, the freespace, and the sign or symbol. Solidity (firmitas), the third pole of the vitruvian triad with utility (utilitas) and beauty (venustas), has remained the great forgotten of these controversies.

The issues of sustainability and life cycles force us today to think about the way in which the function gives shape to the matter.

Obsolescence of function


Built in the 1970s, the small office building in Arcueil that we converted into a student residence in 2010 languished in relative obsolescence. Like many of the “working machines” built in the last fifty years in the Paris region, it had become unsuited to contemporary ways of working. Only via the complexity of French urban planning law was it saved from complete demolition, leading its owners to consider turning it into a student residence. The existing built area was greater than that allowed by the new local land use regulations and the transformation of the existing building has allowed for a larger number of possible rooms than in the construction of a new building.


Permanence of the matter


In order to reopen the field of possibilities and give a new destiny to the building, we conducted an investigation on the material morphology of the building to understand how the matter was shaped by function, and to identify what was firmly determined and what could still change and be rethought.

This investigation revealed that office standards in the 1970s generated on this site a stratification of concrete floor slabs spaced at 2.80 m. These mineral aggregates of cement, sand and gravel, woven by steel rebar, formed two offset series of free trays 16m deep connected by poles and articulated by a circulation core that braced them. The set was covered by a curtain wall made of glass and aluminum sandwich panels that outlined the contours of the two volumes.

This material imprint of the original function had become incompatible with the new functional standards of tertiary programming. However, the structural qualities of this imprint and its intrinsic capacities for evolution paved the way for the possibility of hosting a new occupation as housing.


Erosion and sedimentation


The transformation process initially acted as an erosion force that swept away the most obsolete hardware elements, starting with the curtain wall that contained asbestos and did not provide sufficient thermal insulation. Then we decided to cut the original concrete frame to remove the central circulation core and offer a crossing of the building that connects the two corridors. This subtraction of material was possible thanks to the properties of the original construction. The “column-and-slab” constructive system—a solid slab without beams directly connected to the concrete columns through a mushroom reinforcement design—ensures strong stability of the whole and makes it possible to deconstruct the central core and limit the material needed for bracing in the new configuration.

The extension of the structure with the addition of the passageways carried by poured concrete brackets has affixed a new layer of mineral sediments in which large glass windows with wooden uprights could be embedded. Service through external passageways added to the original structure allowed us to increase the available space for rooms and to introduce new uses that did not exist in the previous function of the building.

The evolution towards a new function corresponds here in a way to a moment of erosion and sedimentation of the first material imprint.

Infrastructural properties


This experience of modifying the functional utility of the building led us to invest in the constructive angle abandoned by functionalist theory. Moving beyond the role of function on the aesthetic form of architecture, here it is the material imprint left behind by the function that guided us in this project.

In The Architecture of the City, in 1966, Aldo Rossi carried a powerful charge against functionalism with the concept of “permanence” of “urban artifacts”. The now famous image of the Arena of Arles as a fortress was the proof that function did not necessarily define form. Rather than expressing functions, architects could henceforth play with a whole grammar of archetypal forms inherited from the past.

The work of transformation, and by extension the design of buildings whose functions would be reversible, calls for an aside—to not be limited to the semiotic considerations of Aldo Rossi. Permanence is above all what function has printed in matter. The contemporary issues of economy of matter and energy push us to be attentive perhaps less to the immaterial symbolic dimension of inherited infrastructures, than to their intrinsic material properties.

Function imprints matter—giving it intrinsic properties. They precede and follow the crystallization of the form / function ratio in a given architecture. The life of a building could therefore be considered as a succession of functional imprints that both add and subtract matter from it. It is from the properties of infrastructures that architecture can be thought of in longer terms, as a cycle of emergences connected by the same material destiny.

Article by Pierre Alain Trévelo, Antoine Viger-Kohler and David Malaud originally published in Identität der Architektur III: Funktion, 2020.