Data Center Building Considerations

Hello, We are doing some preliminary research into relocating our facilities into a new building. This building has not been built and we would like to have some input into at least one of the floors being suitable for a Data Center installation. What I was wondering is if there are any serious design consideration with respect to floor loading, access for things like HVAC/Power, and general convenience issues such as cable management, access security and the like. If anyone has recently gone through any kind of building design or similar work for this type of installation, perhaps you would be able to share your experience or information on the subject. Either a reply to the list or off list would be great. Cheers, Aaron