CONFIDENTIAL ANNEX I PHYSICAL SECURITY Shared Buildings 1. The problem of ensuring that a reasonably high standard of physical security is maintained in shared buildings is made the more difficult when departments handling COSMIC documents are accommodated in the same building as private firms. Such a problem faces certain branches of the Air Ministry and Ministry of Supply, and also the ministry of Transport and the Ministry of Fuel and Power. Only by elaborate and costly structural alterations would it be possible in some cases to obtain in their existing accommodation complete segregation from the private firms and we recognise that any proposal to this end would receive scant support not only on grounds of expense but because in some cases departments consider that such precautions are not justified in view of the few COSMIC documents they handle.