Cross Council guidance on how to write a justification of resources (JoR) is available on the Je-S help pages or in section 2.2.4 of the guidance for applicants.
The role of the JoR is to aid reviewers when assessing proposals so that they can make an informed judgement on whether the resources requested are appropriate for the research proposed. All items requested in the proposal need to be justified in the JoR. The JoR is a mandatory attachment and may be no more than two sides of A4 in 11 point Arial typeface.