Three ways to supply a granny flat
Share the main meter
- No extra set-up cost
- One supply charge
- One bill to split
- No separate record of the flat's use
Best for: Family members living in the flat.
Private sub-meter
- Measures the flat's use
- Fairer split
- Installed by an electrician at your cost
- Charging a tenant from it can count as on-selling
Best for: Splitting costs fairly with family.
Separate connection and meter
- Own account and retailer
- Own concessions
- Clear for tenants
- Network application and electrician costs
- A second daily supply charge
Best for: Rented granny flats and long-term tenants.
What a granny flat adds to the bill
A one-person household in Sydney uses about 3,109 kWh a year in the AER's benchmarks. Added to the main home's meter on the Ausgrid reference price, that usage costs about $1,030 a year. On a separate connection, the flat also pays its own supply charge of about $607 a year, so the total is about $1,637.
| Set-up | Extra cost a year |
|---|---|
| Shared meter, usage only | $1,030 |
| Separate connection, usage plus supply | $1,637 |
Rules to check before charging a tenant
- On-selling energy. Selling electricity to someone else through your meter is generally regulated. The AER's exemption framework sets out when you need to register and what protections the tenant gets. See our embedded networks guide.
- Tenancy law. Your state's residential tenancy rules decide whether and how a landlord can charge for electricity. Your tenancy authority can explain them.
- Network rules. A new connection needs an application to your network, usually through an accredited electrician.
Splitting with family
For relatives, an agreed split based on a sub-meter reading or days in residence keeps things simple. Our splitting electricity bills guide has fair methods.
Questions about granny flat electricity
Not always. It can share the main home's meter. A separate connection and meter suits a rented flat because the tenant gets their own account and retailer.
Possibly, but charging for electricity through your own meter can count as on-selling energy, which is regulated by the AER, and state tenancy law also applies. Check both before you charge.
A one-person flat in Sydney using the AER benchmark of about 3,109 kWh a year adds roughly $1,030 in usage on the Ausgrid reference price, or about $1,637 on its own connection with a supply charge.
Concessions usually require the account in the card holder's name. A tenant with their own connection and account can claim one. On a shared meter, the main account holder's eligibility applies.
Yes. Any work on fixed wiring or the switchboard must be done by a licensed electrician.
Sources
Every rate on this page comes from the regulator or the regulated retailer. Last checked October 2026. Prices include GST unless we say otherwise.