Devolution in the United Kingdom has involved the creation of different quasi-autonomous political administrations. As part of an attempt to encourage institutional learning, there has been a turn to concordats to facilitate cooperation on matters of shared concern, to communicate appropriately and in a timely way, to work in a helpful and open manner and to treat information in confidence. In parallel, the reform of statutory land-use planning systems in the devolved United Kingdom has involved debates around the need for a cultural change to implement a relatively more positive model of planning and development amongst the diversity of stakeholders which have similarly invoked new forms of public diplomacy. The Edinburgh Planning Concordat sets out in some detail the agreed step-by-step actions to be effected and the respective responsibilities of the local authority and developers at the different stages in the land-use planning process. Such anticipated cooperation and coordination in the land-use planning and property development community could suggest a stronger basis for decision making and the articulation of the public interest. Locating the discussion against the backdrop of devolution and planning reform in Scotland, and within theories of new contractualism, this article examines the rise of 'soft' forms of public diplomacy as a means to facilitate cultural change and planning reform.