Might be annoyed if Icelanders take over the building (7)
I believe the answer is:
edifice
'the building' is the definition.
(synonyms)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for edifice that I've seen before include "'Large, imposing building (7)'" , "Grand building" , "Construction" , "Permanent building" , "Impressive building" .)