The short answer is it will cost around $1,200 per square foot to build out additional data center or data closet – though the cost will vary based on equipment and security features implemented. The final figure will depend on the specified fault tolerance and power and cooling capacity of the data center.
In real estate, they say price is determined by location, location, location. A building located in downtown San Francisco is worth many times more than one in rural Kansas. For data centers, cost is determined by the installed electrical and mechanical systems. Well, this may not be as catchy as the real estate phrase, but it is just as true.
Actual building space is a small part of data center costs. Electrical and mechanical systems, including power distribution and cooling, represent about 70% of the construction cost. Since data centers consume 100 to 200 times as much power as typical office spaces, they require significant infrastructure to deliver power and remove the heat.
The other factor is availability. Data centers are rated Tier I, II, III or IV according to the level of built-in redundancy and expected availability. Tier 1 provides a single path for power and cooling distribution, no redundant components and 99.671% availability or 28.8 hours of downtime per year. Tiers II, III and IV offer increasing of redundancy and uptime. At the high end, Tier IV provides multiple, active power and cooling paths, redundant components, fault tolerance and 99.995% availability or less than a half hour of annual downtime.
However, availability comes at a price. Tier IV infrastructure costs more than twice as much as Tier 1.