MEA House and Ryder and Yates offices listed
Two post-war office blocks on Tyneside have been given grade II-listed status.
MEA House in Newcastle and the former offices of its architects, Ryder and Yates, in Killingworth are among 14 "remarkable" buildings listed by the culture secretary.
A campaign to save the Ryder and Yates offices was launched when it was earmarked for demolition last year.
The 20th Century Society said it was a "rare surviving example of a purpose-built post-war architects' office".
The group put it forward for listing in 2010, along with all the other buildings by Gordon Ryder and Peter Yates in Killingworth.
Two - Norgas House and Stephenson House - have since been knocked down.
The architects' engineering research station in the town was listed in 2000.
The 14 offices around England chosen for listing were identified by an English Heritage (EH) project to assess commercial buildings dating from 1964 to 1984.
EH director of designation Roger Bowdler said they showed "how architecture has adapted to recent radical changes in how we work".
The buildings were listed by the culture secretary after recommendations made by EH.
Listed status for the Killingworth offices was granted in October.