ok , buy yourself a single/double consumer unit , screw it to the wooden block on the wall , run the cables (1 lights 2 power) thru to the out building ,,,

remove the main fuse in the celler , and buy 2 insulated blocks , screw those to wall ,, remove the tails from the old consumer unit ,conect to the insulated blocks , and run new tails to the old and the new consumer units 20 quid tops ,,,,redo all the earths to both the boxes


freddy