29 Unambiguous, practical and measurable design standards are needed, which should then be used to define the performance specification. But a common concern expressed during visits was that DfES standards, and the budget set by the DfES PFI 'toolkit', needed to be updated to reflect the demands of the modern curriculum, the needs of today's children and the growing expectation that schools will become more of a community resource. PFI providers are required to meet the outputs agreed in the contract specification - but if these are based on outdated ideas of what constitutes best practice, then problems will persist. Lack of space was the most commonly cited problem. Some schools argued, for example, that they needed two halls because the growing use of pupil testing meant that a hall could be unavailable for other purposes for significant periods. The DfES intends to publish new guidance (available in draft; and, for example, Ref. 9) that should, if incorporated into future specifications, improve this.