Economy of resources, speed of construction, modularity, flexibility and versatility… these qualities inherent to lightweight construction are now combined with the ecological ambitions of frugality: control of the life cycle, energy autonomy and reduction of greenhouse gas emissions. Designed by Renzo Piano, Werner Sobek or Shigeru Ban, from Paris to Tokyo, contemporary lightweight architecture explores modularity, participative construction or miniaturization. They are based on the conviction that building lighter consciously requires less material, uses fewer resources, produces less waste, requires less time to assemble, needs less space, requires exponentially less energy, and symmetrically reduces the carbon footprint of building a home.
This study, conducted on some thirty international projects, reveals the potential and diversity of the constructive systems developed. It demonstrates the ability of these architectures to adapt to the techniques and expectations of their time. Each exploration, re-read in its historical context, using archives, films and models presented in the exhibition, reflects an approach, a technique and a way of living. Redrawn and broken down according to a protocol developed for this event by the Philippe Rizzotti Architecte agency and the IBI laboratory of ETH Zürich, the corpus reveals correspondences and shared qualities. This inventory makes it possible to quantify the constructions, to compare the materials, to analyze the assemblies and to classify all or part of them in order to bring out logics that can be adapted tomorrow.
Presented chronologically, the analysis also offers, for the first time, the opportunity to compare the estimated masses, components, constructive systems of the buildings and their carbon footprint, to compare them to each other and to conventional constructions. The edifying results systematically turn to the advantage of lightweight architecture. The average mass per square meter of the houses presented does not exceed 300 kg/m² when the current houses easily reach 1200 kg/m². Their average corrected carbon footprint is evaluated at 282 kg CO2.eq/m², while the objective of the new regulation is 640 kg CO2.eq/m² with the ambition to be limited to 415 CO2.eq/m² from 2031.