Estimating the space requirements for a small server room

Small companies relocate all the time. Many companies appear to get stuck improvising rooms to put the equipment and often end up using a closet. In such cases, poor ventilation ends up causing undo stress of the equipment and bringing some devices to a premature end. I saw one switch that looked like it had partially melted on the bottom. The textured plastic was smooth and discolored.

A small company will usually have the following:

  • UPS (aka battery)
  • Firewall and/or router
  • Switches
  • Network Attached Storage (NAS) or equivalent (SAN, DAS and so forth)
  • External drives used by IT (for a variety of reasons such as backups or archiving in conjunction with Cloud-based solutions)
  • Servers (Most likely 3-4 boxes of various sizes)
  • RACK (to hold it all in).

Let’s start with assuming you have or want a standard Rack to put all the equipment in. I generally calculate 2′ by 4′ for a single Rack. The rule of thumb is to give yourself 3x the space needed by a rack. If you are using the Rack correctly, you will have servers and other things that need to extend out for maintenance and installation. This brings us to 48sf to safely provide room and could accommodate some limited expansion.

No one recommends using this space as storage. It will get the leftover stuff that belongs to IT but doesn’t have a place temporarily.

This brings us to the ideal small space: 110sf (10’6″ square).


Other considerations:

  • Proper cooling / ventilation
  • Secure (Locked/restricted access)
  • Windowless
  • No plumbing overhead / avoid sprinklers (find alternatives if fire regulations make them necessary)
  • Multiple circuits for power (5-30 NEMA sockets). Place the electrical boxes higher up so as to be closer to the ideal height of the trays. Most use, at a minimum, three 240V/20A circuits. Plan them so no one can accidentally trip over any wires, ever!
  • Two or more separate ISPs
  • ESD tile floors (or concrete) is ideal

Share with us your stories of server rooms and let me know if you agree or disagree with this simple calculation.