White space

White space is the raised-floor or slab area within a data center that houses IT equipment — server racks, network gear and storage — as distinct from "gray space," the mechanical and electrical plant such as chillers, UPS rooms and switchgear that supports it. Colocation providers lease and price white space directly, quoted in square feet or square meters and typically sold per rack or per kW of committed power, while gray space stays on the operator's side of the balance sheet and never appears on a customer's floor plan. In a typical hyperscale building, white space accounts for well under half of total gross floor area once gray space, loading docks, offices and circulation are subtracted. The white space-to-gray space ratio is a rough proxy for a facility's design efficiency: campuses built for very high rack density can pack more IT load into a smaller white-space footprint, shifting a larger share of total building area toward support infrastructure rather than shrinking it.