Dog in front of building, something well worth having (6)
I believe the answer is:
basset
'dog' is the definition.
(basset is a kind of dog)
'front of building something well worth having' is the wordplay.
'front of' suggests taking the first letters.
'something well worth having' becomes 'asset' (I've seen this before).
The initial letter of 'building' is 'b'.
'b'+'asset'='BASSET'
'in' acts as a link.
(Other definitions for basset that I've seen before include "Hare-hunting hound among beasts" , "Beasts (anag.)" , "Short-legged hound that hunts hares" , "Hound (named Fred?)" , "Sturdy hunting dog" .)