Uncertainty in building inspection and diagnosis: A probabilistic model quantification

Clara Pereira; Ana Silva; Cláudia Ferreira; de Brito, J; Inês Flores-Colen; José Silvestre

Key information

Authors:

Clara Pereira (Clara Isabel Fernandes Pereira); Ana Silva (Ana Filipa Ferreira da Silva Cigarro Matos); Cláudia Ferreira (Cláudia Alexandra Rocha Ferreira); de Brito, J (Jorge Manuel Caliço Lopes de Brito); Inês Flores-Colen (Inês Flores-Colen); José Silvestre (José Dinis Silvestre)

Published in

September 1, 2021

Abstract

In the field of building inspection and diagnosis, uncertainty is common and surveyors are aware of it, although it is not easily measured. This research proposes a model to quantify uncertainty based on the inspection of rendered façades. A Bayesian network is developed, considering three levels of variables: characteristics of the building, façade and exposure conditions; causes of defects; and defects. To compute conditional probabilities, the results of an inspection campaign from the literature are used. Then, the proposed model is validated and verified using inspection results from another sample, the combination of a strength-of-influence diagram and sensitivity analysis and the application of the model to a case study. Results show that the probabilities computed by the model are a reasonable representation of the hesitancy in decision making during the diagnosis process based only on visual observation. For instance, design and execution errors show lower probabilities due to not being verifiable a posteriori without detailed documentation. The proposed model may be extended and replicated for other building materials in the future, as it may be a useful tool to improve the perception of uncertainty in a key stage of building maintenance or rehabilitation.