The UN Convention on the Rights of Persons with Disabilities is the first international human rights convention to state expressly that discrimination includes the failure to provide reasonable accommodation. The duty has been described as transformative but has also been critiqued for its lack of structural impact. This paper evaluates the transformative potential of the reasonable accommodation duty encompassed by the Convention, and considers how its potential can be realised. It argues that the duty is transformative because of the substantive equality it provides for individuals, and because it requires both active engagement with persons with disabilities and proactive consideration of barriers to inclusion, in multiple contexts. However, it contends that full realisation of the duty's transformative potential depends on appropriate legislative formulation. This may be a problem in dualist states where application of the Convention is not automatic and pre-existing legislation may be perceived as satisfying the obligation. The paper supports this contention with an analysis of Irish law, arguing that the full transformative potential of the reasonable accommodation duty has not yet been achieved in Ireland, and identifying the reasons for this. The paper examines the practical consequences of inadequate implementation and highlights pitfalls and best practice.