Site selection for new server environment

Clarifications

Since you seem to be saying you will be hosting the servers yourself, but as for physical location attributes...
1)Affordable T1/E1 connections available.
2)Dust free (as possible) room.
3)Low humidity in room. (watch static build up from this).
4)Reliable power to feed the UPS units.
5)Constant temperature in room.
6)Access control on door to room.

These are some thoughts on an ideal. Over all heat moisture and excessive dust are to be avoided at all cost.

The only advice I can pass on is from my truck driver brother,

Make sure you know the weight limit of the elevators.

Make sure that there are more than two fire escapes, reason being a new install for a major Australian bank in North Sydney required a fire escape to be isolated for 3 days so they could build a ramp up the stairs. Server weighed 1500kgs (including 100kgs for the trolley). Elevator limit was 1300kgs, his stairclimber had a 700kg rating.

If you raise the servers off the floor, make sure that the flooring is capable of withstanding greater weights, they pulled a cluster of 6 (out of 24) of the raised air conditioned platform and replaced it with one of the four specially designed new servers. He didn't finish lunch before he had to come back and get it of the platform.

It was at a 45% angle leaning on another cluster after the floor collapsed!!!