Building, putting up (8)
I believe the answer is:
erecting
This clue is a double definition.
'building' is the first definition.
(I know that erecting is a type of building)
'putting up' is the second definition.
('erect' can be a synonym of 'put up')
(Other definitions for erecting that I've seen before include "Building something" , "Building, putting up" , "Constructing" .)