On Tue, 7 May 2019 11:50:14 +0100, Chris Green wrote:

I've just realised that the toilet extract fan I'm installing is
totally inaccessible from the toilet cubicle itself because it's an
inline fan with ducting either side that will be installed in the
eaves roof space.

So I guess the isolation switch needs to be somewhere in/around the
roof space where the fan is. There's absolutely no point in putting
it in the toilet cubicle.

Same configuration here- so isolation switch is on adjacent joist so
I /know/ I'm safe when cleaning the fan...