Challenges of current regulations for building permits under digitalisation: a Portuguese case-based analysis

The granting of building permits has presented many issues over the years. Despite the efforts to improve the quality and performance of building permit processes through digitalisation and the implementation of automatic compliance checking systems, many challenges remain unaddressed. A key obstacle is the interpretation of regulatory requirements, which leads to inconsistent design assessments due to the subjective and ambiguous nature of many rules. While previous studies have addressed this issue by systematising and classifying ambiguities, a deeper analysis is necessary to examine these ambiguities beyond merely identifying them. This paper aims to analyse the underlying aspects of these ambiguities and challenges in detail, based on a comprehensive study of permitting rules conducted in collaboration with the Municipality of Lisbon (Portugal). Sixty rules were selected and interpreted using rule interpretation frameworks and discussed with municipal technicians in interviews. The exploratory research classified the analysed rules into four main types of challenges: Ambiguity, Dependency, Geometric Complexity and Jurisprudence. Representative examples of each type are presented. The findings of this research highlight the need to adapt the regulatory framework to be aligned with digital building permits and provide valuable insights for policymakers and municipalities.