Tier-3 "standalone" facility

[Zitibake]

Glossies from the Uptime Institute mention that Tier-1 and Tier-2 datacenters are typically "tenant" facilities, while Tier 3 and 4 are "standalone".

Anyone know what "standalone" implies? If the datecenter is the building owner, but leases rooms to tenants, would that describe "standalone"?

Also, it's unclear whether "standalone" is a requirement of Tier3/4 certification or is just "typical". I know of one datacenter claiming Tier 4, that is a tenant in a larger building.

Standalone is renting an entire building or owning an entire building and being the only tenant in said building.

[KenB]

By standalone, I think they mean a purpose-built facility, rather than a data center inside an office building.

Ken