Not separate wire, just one big enough to carry currents(?) for 2 properties.
Level 1 electrician does it from meter box to granny flat;
Level 2 electrician does it from meter box to street.
http://www.davefenechelectrical.com.au/
Call these guys, very professional, good pricing.
Cost me $800-$1000 from memory.
Bit more when I had to upgrade the main power line.
