What a fellow needs a bit of help in building (6)
I believe the answer is:
chapel
'building' is the definition.
(chapel is a kind of building)
'what a fellow needs a bit of help in' is the wordplay.
'what a fellow needs' becomes 'capel' (I can't justify this - if you can you should give a lot more credence to this answer).
'a bit of' suggests taking the first letters.
'in' is an insertion indicator.
The first letter of 'help' is 'h'.
'capel' going around 'h' is 'CHAPEL'.
Can you help me to learn more?
(Other definitions for chapel that I've seen before include "Nonconformist building (with a father!)" , "Nonconformist church" , "Place of worship set apart in church or cathedral" , "Place used for Christian worship - smaller than cathedral" , "Union members" .)