Alan Rawdin, Ali Khudhair, Haijiang Li
While many regions have accelerated Building Information Modelling (BIM) through government mandates, many jurisdictions must pursue adoption without centralised enforcement. This raises a key question: what governance arrangements enable consistent BIM information management and ISO 19650 alignment in non-mandated settings? This paper addresses this question through a longitudinal case study of Wales, a devolved UK region without a devolved BIM mandate, programmatic funding, or a coordinated implementation framework. Using a qualitative-dominant mixed-methods design comprising stakeholder workshops (2017-2023), semi-structured interviews, and a structured survey of contractors and local authorities, the study examines how stakeholders interpret and operationalise ISO 19650 in practice. The results indicate that reported BIM tool use is widespread, yet formal standards-aligned implementation is substantially lower, revealing a persistent gap between software adoption and ISO 19650-oriented information management. Across data sources, recurring governance constraints include weak and inconsistent client-side commissioning of information requirements, project documentation that is produced primarily for compliance rather than embedded coordination, and ambiguity in information management roles and accountabilities across the project lifecycle. Rather than treating mandates as a prerequisite, the study argues that governance maturity is a primary enabling condition for ISO 19650 alignment in non-mandated contexts. The paper contributes empirical evidence on bottom-up BIM governance and proposes practical, non-legislative interventions, including shared regional templates, a knowledge hub to translate requirements into practice, role-specific training emphasising applied competence, and digital support for validation and assurance, measures intended to reduce interpretive burden and improve consistency across the supply chain.