Put the server room on a separate electrical grid so you can easily install a backup generator. Since most smaller gas-fired generators are piston, they send out dirty power. To fix this only use 'Double Conversion Online UPS' which takes the dirty power and creates a perfect sine wave albeit using the battery for this so not as efficient as cheaper direct UPS.. If you use a regular APC UPS and the generator kicks, the UPS will freak and and die and it switched back and froth from battery too quickly. Buy a AV Tech environmental monitor http://avtech.com/
and monitor for heat, fire, water, and humidity. Also, you might want to log card scans to get into the server room since it holds expensive equipment that could be stolen, then you can prove whose card was used to enter. Put the server room on its own subnet and firewall it from general network and Internet. If an attack happens, then you can simply unplug the external networks cables. Honey Pot and IPS monitor are nice additions.