From traditional surveying to digital expertise

Today, heritage architects are very often called upon to carry out assessments of structures with significant heritage value of all kinds. This meticulous work can be divided into two main stages: gaining an understanding of the building in its current condition (observing symptoms and defects) and identifying possible solutions (diagnosis and treatment).

Understanding the history of a building since its construction makes it possible, during the inspection of the building and the site on which it stands, to identify the characteristics to be preserved and the composition of existing construction systems. Subsequently, the identification of symptoms and defects is quantified through data compilation. Data analysis then enables the diagnosis and guides decisions regarding interventions—whether the approach should be minimal, focusing on repairing existing components, or more interventionist, involving the replacement or restoration of components lost over time. Diagnosing the building’s condition helps determine the most appropriate heritage intervention strategy.

Undeniably, over the past few generations, new technologies have emerged, asserted themselves, and become integrated into the practice of architecture. Traditionally, heritage architects have relied heavily on documentary, iconographic, and historical research for much of their work. However, as time goes by—and despite considerable efforts—it becomes increasingly difficult to retrieve original information for certain types of buildings. Over the years, buildings continue to evolve and undergo numerous transformations, rendering many of these sources inaccurate or outdated. Architects must therefore refocus on the most reliable source of information available: the building itself.

In the past, all investigations would have been carried out manually—measurements taken with tape measures, drawings made with paper, pencil, and square, and so on. Today, digital technology allows for the generation of 2D and 3D images and supports the management of collected data through a variety of new investigative methods. For example, laser scanning surveys produce point clouds that precisely illustrate a building’s three-dimensional dimensions, including all deformations and structural anomalies. Photographic and thermographic surveys conducted by drones reveal a building’s symptoms and behaviour under different conditions. Hygrothermal surveys using probes enable multiple simulations through wall assemblies based on their compositions. Ground-penetrating radar surveys make it possible to understand internal compositions without resorting to destructive exploratory openings.

Much like healthcare professionals use X-rays, ultrasounds, endoscopies, and blood tests to analyze what is invisible, heritage architects examine buildings through various types of surveys and material sampling for laboratory analysis. That said, certain traditional methods—such as close-up inspections, exploratory openings, and hammer testing—remain time-tested and highly effective techniques.

Without question, the heritage architect continues to evolve and adapt by combining traditional survey techniques with the support of new technologies. This hybrid approach enables the management of large volumes of data, which can be compiled to identify trends across each façade according to different exposures to the elements.