Chunk of bituminous tar's ignited one's house (4,4)
I believe the answer is:
star sign
'house' is the definition.
(I've seen this before)
'chunk of bituminous tar's ignited one's' is the wordplay.
'chunk of' indicates the answer is hidden within the clue.
'STAR SIGN' is hidden in the letters of 'bituminous tars ignited ones'.
(Other definitions for star sign that I've seen before include "Archer for one" , "Eg, Leo or Aries" , "Leo perhaps" , "Zodiacal figure" , "Eg, Taurus" .)