The dedicated space requirements given in the technical manual are default guidance, for situations where it is not possible to demonstrate the required size based on known waste streams.
Compliance can, therefore, be achieved provided that it is clearly demonstrated and evidenced that there is adequate justification for the type of facilities & size of waste storage provided, and that the assessor is satisfied that the sizes and facilities meet the criteria based on the building type, occupancy and the likely waste volumes generated as a result of these.