Glass-enclosed spaces in USSR mono-building (8)

I believe the answer is:

sunrooms

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'glass-enclosed spaces' is the definition.
I can't tell whether this definition defines the answer.

'ussr mono-building' is the wordplay.
'building' indicates an anagram.
'ussr'+'mono'='ussrmono'
'ussrmono' anagrammed gives 'SUNROOMS'.

'in' is the link.

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I've seen this clue in the Sydney Morning Herald.

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