Building Recpvery with a View to Duration

In performing building recovery, we are obliged to adopt materials, products and technical solutions that have little or nothing to do with those originally used in the building of which they will come to form an integral part. Almost always, buildings undergoing recovery were constructed in periods even far removed from the time when subsequent modifications are made. Both material components and organizational aspects vary with time, so the solutions used today differ enormously from those available at the time of the building’s original construction. The introduction of such innovation carries the risk of a behavior in service that may even interfere with the durability of the system as a whole, and of its various parts, because the changes introduced with subsequent repairs are often incompatible, or at least difficult to integrate, with the original parts. It is by no means easy to evade this problem because of the often definitive loss of the materials, products, elements and expertise of times gone by. Given this state of affairs, a fair proportion of the architectural heritage of the twentieth century, for instance, is changing face due to essential building recovery measures (including maintenance, repairs, replacements, refurbishments, etc.), becoming different from what it originally was. While this situation must be accepted to some degree, if we are to hand down at least a part of the culture of a given period to future generations, we must face the fact that introducing innovation in many cases means paying a price in terms of reliability and durability – a price that, in a sense, is proportional to the degree of extraneity of the modifications with respect to the original. So what is the most suitable approach to ensure the best results in terms of reliability and durability? An attempt is made to answer this question.