"Stephen Gower" wrote
| Could you clarify what I've read on Google groups?
| * For an outbuilding, a separate TT earth is required/recommended,
| provided by an earth rod.

Required if the supply to the house is PME or the outbuilding is more than a
certain distance away.

| * The power itself is provided by a 2 core SWA cable carrying live
| and neutral.
| * The armour of the SWA is connected to earth.
| Is this correct, and to which earth should the SWA armour be
| connected, the house, or the garage?

Yes, and the SWA is earthed at the house end. At the garage end you can
either use an insulated CU or a special gland which insulates the armour.

Owain