I don't know the current (pun alert) zone restrictions in the UK, but in France they are zone 1 immediately above the bath/shower and 2.25m above the bottom of either, zone 2 is 600mm beyond the edge of those anything beyond that is not classed as a zone, sockets, switches and appliances can be in that area, there are some other extensions to the zones for projecting shower heads where the volumes of both zones are extended, but then all circuits in France are protected by RCD's in my own place the bathroom/shower rooms are all protected by individual RCBO's to each appliance, radial and lighting, thought it may be of interest and promote some discussion on the safety of RCD/RCBO's within a potentially wet area.