This might not be relevant but --
It might not be, depending on where FCU is installed?
That's why I got involved, the original question and following posts, were regarding the fitting/cabling to an outside light and whether this was deemed notifiable.
So I stepped in with my size tens....
So it may not be relevant but might.The real issue here is where the FCU or S/FCU is located, if it's in the kitchen it will be notifiable as you are altering a circuit which comes under the same regulations as special locations/special installations.
If the cable to the outside light fitting, enters the fitting directly without any external joints and the light is fitted to the side of your house, it's not notifiable.
So the matter would be where is the FCU or S/FCU going to be installed?
We need to know where the alteration/addition to the circuit is being carried out?