Marble building with government offices? (9)
I believe the answer is:
whitehall
'with government offices?' is the definition.
The definition suggests a singular noun which matches the answer.
'marble building' is the wordplay.
'marble' becomes 'white' (I can't justify this - if you can you should believe this answer much more).
'building' becomes 'hall' (hall is a kind of building).
'white'+'hall'='WHITEHALL'
Can you help me to learn more?
(Other definitions for whitehall that I've seen before include "admin staff here" , "Administrators" , "Government policy" , "Street symbolising British government" .)