I for one would not be expecting to find wiring under exterior render,
I don't think many others would be either.

The time you'll get in trouble is when the
rendering gets redone, and someone puts a chisel through it. So its
best to put a cover over it before the render.

All cables should run vertical or horizontal of any electrical point or run
in the zones of 150mm from corners or ceiling or a depth of more than 50mm
if none of the above then the cable must be protected by a metal EARTH
sheath

A handy group, uk.d-i-y! I was so busy thinking about damage to the
cable by weather that it it didn't occur to me to think of damage by
human. Perhaps I will abandon the idea of running the cable behind the
timbers and be sensible like everyone else, run them in front and
disguise with a bit of acrylic paint camouflage when the time comes.

It has been worthwhile thinking about electrics at this stage though
cos I have fixed battens between the studs which the switch boxes can
be screwed to

Thanks all
Anna
~~ Anna Kettle, Suffolk, England
|""""| ~ Lime plaster repairs
/ ^^ \ // Freehand modelling in lime: overmantels, pargeting etc
|____| www.kettlenet.co.uk 01359 230642