What is the right balance of output based versus standardised specification, when considering the twin objectives of accessing greater contractor innovation and reducing costs? 

See Q25a - that response was given in particular relating to relatively standard social infrastructure assets. However, we do not consider that a universal approach can be applied. For example in roads procurement it may be that a significantly earlier contractor involvement before detailed routing and major civil engineering decisions have been taken could bring benefits, though the challenges of interacting such an approach with the legal frameworks for project promotion could be substantial.