OP
1shortcircuit
Still possible to find the approximate mid point for a split by checking resistances.
Oh most definitely, I should have emphasised more. Great care will be required to ensure that all outlets are tested so that the labelling of the consumer unit can be done correctly and in a way that will never put anyone at risk ie Front radial, rear radial or up and down. This could become less straightforward if after finding the mid point there is power on both floors.
:thumbsup