Ray tracing is a well known technique for producing realistic computer images. The computational requirements of this method are such that optimisation techniques, for example space subdivision, must be used if complex scenes are to be rendered in reasonable times. Constructive solid geometry (CSG) is a method for describing the geometry of complex scenes by applying set operations to primitive objects. The status tree approach has been used successfully within ray tracing to evaluate CSG structures. This paper proposes a combination of the status tree and space subdivision techniques as a means to improve further the efficiency of ray tracing.