A main installation is fed with 16mm cable to a junction on the side of a house. The house has a flat, tin roof.
A granny flat is built on. Can I tie in to the junction box, will be using 16mm armoured cable, a main breaker + E/L at the new flat with its own DB? I went through the book a few times, and I cannot find a reference that says its not allowed, do not want to lift the roof to chase into the old DB??