Mike Smith wrote:

I would like to move the bathroom light switch to
inside the bathroom -- in fact immediately the other
side of the wall to the existing switch would be fine.

Well go on then ;-)

Does anyone know of any single-pole switches that can
be installed in Zone 3?

Pretty much any of them. You need to apply common sense though. If it is
likely to get either drenched or soaked by steam frequently then one
with a suitable IP rating would be better. In most bathrooms a normal
switch is often OK (and not precluded by the regs in zone 3)

The "ideal" solution of fitting a pull cord switch
doesn't appear to be possible as I have no access to
the bathroom ceiling void (because there isn't one,
its a flat roof)

Flat roofs are not usually infinitely thin and hence typically have some
void equal to the joist thickness that was used to make them. This is
usually enough to hide a cable. Much depends on how much hacking /
making good you are prepared to do. (also think laterally - if the room
is tiled and you need to chase a cable into the wall, you can often get
away with chasing the other side of the wall!)

p.s. why it is acceptable to use a switch outside
the bathroom door with wet hands but not inside
is another question...

A semi serious answer to that is that you are slightly less likely to be
starkers and dripping wet outside of the bathroom.


--
Cheers,

John.

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