Our present supply is 100 amp rated but we have an induction hob which will overload the present supply if we simply add the annexe's needs onto our existing supply.
The electrician has recommended we either get a 3-phase supply or ask our supplier for an additional meter - but there doesn't seem to be anything on the ovo website about this.
Best answer by Transparent
Well, considering this is your first post on the OVO Forum, you've chosen a good one! I'm sure there are several of us who can help. I don't know the complete answer, so I'll comment on the technical bits and hope that others can respond to the rest. Your electricity supply, including the Main Fuse and the Meter, are the property of the Distributed Network Operator (DNO) for your geographical region. You need to start communicating with the one for your area about having a new/upgraded connection. You can download a PDF to tell you how to go about this from here. 3-phase has a number of advantages, especially if you want to feed solar/wind power back onto the National Grid. You will be allowed to connect up to 3x 16Amp renewable-energy generators, which could be very valuable! And if you ever buy an electric vehicle, you can have a high-speed charger port. However, I don't know of any Domestic Energy Supplier who could fit a 3-phase Smart Meter, and we will soon all need one. In your case this probably isn't a problem.
Your electrician could divide the phases
- Main house
The first two need their own (Smart) Meter. Thus you can have separate bills for the Granny Annexe if you wanted. The spare phase should still be terminated to a separate 100A "Switch Disconnector" and simply left there in case you later require it. The presence of the Switch means that an electrician won't have to recall your DNO to site if something is later connected to this phase. Have a read of this thread where an OVO Forum Moderator discusses 3-phase with another customer. Ask again here if you need further clarifications.