Splitting your IT equipment across multiple computer rooms is a good way of increasing resilience and reducing your risk, right? Not necessarily!
Unless system components are duplicated or mirrored to give true resilience, you might actually be lulling yourself into a false sense of security.
Many systems have a number of inter-related components, loss of any one of which would stop the system working. In this instance, simply splitting them across different rooms may actually increase the risk of failure, as there are now two or more environments that can go wrong.
Rather than spending your money on a second computer room, it may be a wiser investment to spend it on increasing the environmental protection and controls at your existing location instead. At the very least, ensure you do a proper risk assessment before making the decision.
So this is a case where it might make more sense to keep all your eggs in one basket, but to make the basket itself safer.