Structural repairs of structures with steel Adaptation to new loads, thermal and acoustic standards

With the development of building rehabilitation at the end of the 20th century, techniques for repairing and bringing buildings up to standard have evolved considerably. Carlo Scarpa's work paved the way for transformations that were more conceptual than simple rearrangements without spatial considerations.

Iconic projects by renowned architects such as Rem Koolhaas for the Prada Foundation in Milan and Galeries Lafayette in Paris, or Herzog & de Meuron for the Tate Modern in London or the Caixa Forum in Madrid, have brought spectacular yet respectful and sustainable projects to the forefront of the design scene. They have definitively erased the idea that new is better than refurbishment, and unleashed boundless creativity.

This reuse of existing buildings involves different types of specific intervention, which can be grouped into three families as follows.

Adapting to a new use may reveal weaknesses, or even inabilities, in the existing structure to meet the expected acoustic and thermal performance. We're thinking here of the acoustic performance of a floor or a partition between two dwellings. In such cases, it is necessary to upgrade the building, using corrective methods based on our solutions for thermal upgrading of facades and roofs. Resolving acoustic and thermal shortcomings has become a key issue in policies to rehabilitate and transform existing buildings, the foundations of which were laid and quantified during the Grenelle environmental summit. These solutions are discussed in the light of recent examples of buildings converted for other uses.

This exercise also involves adapting buildings to new needs by bringing them into line with current standards. We're talking here about new load definitions brought about by a change of use, such as the conversion of housing into offices. Changes in regulations, such as snow or wind maps, also lead to automatic changes in design loads when adapting existing buildings. This category also covers the addition or transformation of existing circulation systems, some examples of which are given below. The presentation focuses on the retrofitting of buildings to add balconies, mezzanines, staircases or elevators. Here, steel provides clever, lightweight and economical solutions, applicable to all types of construction.

New concepts are emerging that advocate the reuse of building materials to reduce recycling phases as much as possible. These "Cradle to Cradle" techniques are highly applicable to rehabilitation. They are succinctly illustrated through two examples: the European Court of Justice and the Halle d'Annecy.