Buildings envelope anomalies: A visual survey methodology

The early deterioration of social housing envelopes reflect their low durability. An evaluation methodology to estimate social housing envelope degradation level was developed which has been applied to a set of social housing. Following this study, the methodology revealed adequate for any sort of buildings, taking into account their specific features that necessitate some methodology modifications. To support the visual survey of the external building envelope, tables applying the Failure Mode and Effects Analysis (FMEA) were used to analyse the principal causes and effects of the anomalies identified. To evaluate the main visible anomalies on their external envelope, two evaluation scales have been created: one for the degradation degree applicable to each typified anomaly and the other for the performance level of each building respect to a set of functional requirements. The degradation level of each of the principal anomalies was determined as well as the evaluation index of the building envelope. Degradation evaluation results were obtained through visual survey and were aggregated by two methods developed for the research: one based on the Hermione aggregation method and the other on the results of the inquiry to tenants based on a multi-attribute analysis attending to the relatively importance (weight) of the evaluated requirements. Each attributed weight was obtained throughout the expressed opinion of technicians and specialists from the construction sector.The aim of this paper is to present the visual survey methodology of the envelope degradation level and the results obtained for the degradation degree of each typified anomaly, and the performance level of each building in respect of a set of functional requirements.

Research highlights
► We developed an evaluation methodology to estimate building envelope degradation level.
► To support the visual survey were applied the Failure Mode and Effects Analysis.
► To evaluate the main visible anomalies two evaluation scales were created.
► Following this study, the methodology revealed adequate for any sort of buildings.
► We conclude the evaluation method is an essential tool for assessing the housing stock.