I will be having a brick built shed in the rear garden and will require electricity in it. I know that I will either have to get the work check for Part P or get an electrician to do the work. But can anyone tell me please what depth would the armoured cable have to be laid? The reason I ask is that the only way from the consumer unit to the shed will be through the back of the garage and across the top of a drainage channel/pipe, which I don't think is more than about 50 cm deep and I wouldn't want to damage it.