Great question — answering as the UphillTech team:
As far as I know, UNIT's headquarters buildings have never had names; there's never been any signage identifying them as anything other than "UNIT headquarters": Even in modern Who, the UNIT HQ doesn't have a name of it's own, because it's in the Tower of London.
Full answer by KutuluMike: https://movies.stackexchange.com/a/40930 (CC BY-SA 3.0).
Need it done for your business? UphillTech.
