Sad to publish building’s final design (9)
I believe the answer is:
blueprint
'design' is the definition.
(synonyms)
'sad to publish' is the wordplay.
'sad' becomes 'blue' (similar in meaning).
'to publish' becomes 'print' (synonyms).
'blue'+'print'='BLUEPRINT'
'building's final' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for blueprint that I've seen before include "Formula" , "Original plan influencing subsequent decisions" , "Original design" , "Technical drawing" , "Prototype" .)