Managing a bit of building (6)
I believe the answer is:
coping
This clue is a double definition.
'managing' is the first definition.
('cope' can be a synonym of 'manage')
'a bit of building' is the second definition.
('coping' is part of 'building')
(Other definitions for coping that I've seen before include "Contending with - wall masonry" , "Capping along the top of a stone wall" , "Managing, getting by" , "wall feature" , "Rubbing along" .)