As i said: It is not meant to be a building, but more like the Shimmering Portal or even the Totems like the Stasis Totem.
If it was meant to be a building then the building sequence would at least be 60 seconds long. Along with an entirely different way of "birthing" it.
In it's current state it is meant to be Summoned by an experienced Warlock and to be used as a temporary Gateway between two points.