Purpose: COVID-19 highlighted the potential value of improving knowledge sharing (KS) processes among hospital estates and facilities management (HEFM) departments. Organisational trust (OT) is a recognised predictor of KS interactions, but the interplay of impersonal and interpersonal OT components is yet to be investigated fully. In response to recent calls, this study aims to explore the effect of organisational features on personal trust and OT components required for KS episodes, in the context of the English National Health Service (NHS). Design/methodology/approach: A qualitative, exploratory grounded theory approach was selected, using primary data from 22 semi-structured interviews and secondary data from grey literature. A model of trust for KS among employees from geographically distributed units with pooled interdependence was synthesised from a review of the literature and used to connect the organisational features to different trust mechanisms. Findings: This study identifies four organisational features with a compound barrier-effect on impersonal-based OT, interpersonal-based OT and personal trust for KS interactions: lack of professional development, inappropriate reward and incentive systems, reorganisations/organisational change and benchmarking. Research limitations/implications: This study sought to generate theory about the interplay of organisational barriers and trust components required for KS, not to describe HEFM KS across the entire NHS. Future studies with more comprehensive data collections can build on this exploratory study by quantitatively testing the compound barrier effect of the organisational features. Practical implications: Practitioners can benefit from the insights into the barriers inhibiting trust mechanisms required for effective KS processes. These can inform policymakers in English and potentially other health-care systems in designing enhanced collaborative arrangements, which are required as future crises, e.g. pandemics and climate change hazards, will require increasingly complex solutions. Originality/value: This study addresses the interplay between personal trust, impersonal OT and interpersonal OT for KS by identifying the compound barrier effects of underlying organisational barriers common to personal trust and OT.