Building material rating revised by English (7)
I believe the answer is:
granite
'building material' is the definition.
(I know that granite is a building material)
'rating revised by english' is the wordplay.
'revised' indicates an anagram.
'by' means one lot of letters go next to another.
'english' becomes 'e' (abbreviation).
'rating' is an anagram of 'granit'.
'granit'+'e'='GRANITE'
(Other definitions for granite that I've seen before include "Igneous rock, generally composed of feldspar and mica and quartz" , "determination" , "Coarse-grained igneous rock" , "Get rain (anag) - rock" , "A very hard rock from Tangier" .)