This goes without his planning cover for house (9)
I believe the answer is:
thatching
'cover for house' is the definition.
(as in a thatched roof)
'this goes without his planning' is the wordplay.
'goes without' indicates named letters should be taken away.
'planning' becomes 'hatching' (as in hatching a plan).
'this' with 'his' taken out is 't'.
't'+'hatching'='THATCHING'
(Other definitions for thatching that I've seen before include "roofing material ?" , "Roofing with straw or reeds" .)