Comment Having gone through this a few times... (Score 3, Informative) 422
A dedicated server/telco room is a must. Room size determination is simple as taking our current rack number and multiple by two. Add 3' ft in the back and 6' in the front. I would also install a dedicated electrical panel. It makes adds/moves/changes much easier later. Also I would hammer on the electrical contractor to insure there is a good ground to the panel. This will mitigate a ton of "transient" problems later. I would also install four 2" conduits to a outside pull box for telco access. That way the local telcos don't tear up your new building trying to bring service in. It also forces the demarc to be inside your server room which makes issues easier to deal with later. Make sure one side of your wall has 3/4" ply/OSB to act as a peg board. A full 4x8 sheet is good enough. Also I would speak with the fire contractor about installing a dry system inside your server room. That way the sprinklers don't ruin your expensive equipment. I would also go for a dedicated AC unit. To size take your current BTU needs and multiple by two. I would also install a solid door with a punch key keypad. You can get inexpensive ones at local hardware store. Lastly since you guys are most likely a warehouse style building so I would not run conduit unless I had too. I would use wire troughs or hangers with shielded CAT6 cable. That way you don't trap yourself later with conduit. If you want to hide the cables then paint them. There are a bunch more suggestions but those are the big ones.