Granny Flat Electricity and Water: Connection and Metering Checklist
Plan electricity and water for a granny flat. Compare supply checks, connection scope, meters and billing with a practical builder responsibility worksheet.
The short answer
Before ordering a granny flat, get four things recorded separately: how electricity and water will reach it, whether the proposed supply is suitable, how usage will be measured, and who will receive the bills. “Plumbing and electrical included” is not a complete answer.
A meter can record consumption without creating a separate utility account. Hunter Water, for example, says its separately metered single-title multi-dwelling properties receive one bill with each meter's usage itemised. That is a specific provider arrangement, not an Australia-wide rule. Check the proposed arrangement with your own provider before paying for it. Hunter Water's separate-metering guidance.
Use this checklist to compare project scope. It does not determine whether a dwelling is approved or what an owner can charge an occupant.
Start with a marked-up site plan
Ask the builder to mark the point where its plumbing and electrical work ends. For a factory-built module, this may differ from the point where the site's services begin. Get both points shown on the same plan.
Record the main house, proposed granny flat, existing meters, proposed service routes and any shared outdoor facilities. Then ask who will confirm the existing services' locations and condition. A neat line on a sales drawing is not evidence that the route has been investigated.
Give the builder your intended use: family accommodation, proposed rental, or still undecided. Include planned hot water, cooking, heating and cooling equipment. Mention existing solar, batteries or a proposed vehicle charger so the electrician can assess the whole brief.
Keep wider delivery and foundation questions in the prefab granny-flat guide. This worksheet focuses on the service work that can sit between the building quote and the finished project.
Electricity: get the connection and account tasks named
Ask the electrician and relevant network provider what assessment is needed for the existing supply and proposed demand. Do not assume that room for another meter proves the supply is suitable for two homes.
Ausgrid's new-connection page, for example, separates applications by connection capacity and refers to total maximum demand when connecting multiple premises. Your electrician should identify the applicable process for your address; those application categories are not a sizing guide for a homeowner. Ausgrid's new-connection information.
Get written answers to these questions:
- Who assesses the existing supply, switchboard and proposed equipment?
- Is the proposal an alteration to an existing connection or a new connection?
- Who submits applications and responds to requests for more information?
- Which cable route, excavation, switchboard work and reinstatement are included?
- Who arranges the meter, account setup and final energisation?
- What must be finished before those appointments can happen?
The Australian Government's Energy Made Easy guidance tells people moving into a newly built property to contact an energy retailer early to arrange a connection and confirm whether new meters are needed. Use that as a prompt to coordinate the account side of the project, alongside the physical work. Confirm the process and timing with the retailer serving your address. Energy Made Easy: moving to a newly built property.
Water: ask what the proposed meter actually does
“Separate water meter” is too vague for a quote. Ask for the provider's name for the arrangement and who owns, reads and maintains each meter.
Icon Water's guidance distinguishes its own metering from private meters used for internal monitoring. It says private meters are the owner's responsibility and are not read, maintained or repaired by Icon Water. Its secondary-residence guidance also distinguishes an independent service from a privately monitored meter without a dedicated service line. These examples show why the ownership and billing questions matter; they do not establish eligibility for another property or water authority. Icon Water's metering guide.
Ask the water provider and licensed plumber to confirm:
- The proposed supply route and any assessment of available supply and pressure.
- Whether an application, changed pipework or additional service is needed.
- The meter arrangement, access requirements and maintenance responsibility.
- Whether the provider will issue separate bills or itemise usage on one bill.
- Any change to ongoing service charges, as well as installation costs.
Record outdoor taps, irrigation and other shared uses on the plan. Ask which meter would record them. Keep sewer, greywater and stormwater scope separate: measuring incoming water does not answer how wastewater will leave the building. See the wastewater and greywater guide for that part of the brief.
Copy this responsibility worksheet into each quote request
For every row, record a named person or business, whether the work is included, allowed for, excluded or unresolved, and the document supporting the answer. “Owner to arrange” needs its own quote and timeline.
| Decision or work | Written answer to obtain | Evidence to keep |
|---|---|---|
| Existing services | Who locates and assesses them? | Site investigation scope and marked plan |
| Supply suitability | Who confirms the proposed demand can be served? | Provider or trade assessment |
| Connection boundary | Where does each contractor's work start and stop? | Drawing with labelled connection points |
| Site connections | Which routes, lengths and reinstatement are included? | Measured scope and exclusions |
| Applications | Who submits, pays and follows them through? | Application list and responsible contact |
| Meters | What arrangement is proposed, and who owns and reads it? | Provider confirmation and meter scope |
| Accounts and charges | Who receives bills, and what recurring charges apply? | Current provider advice |
| Completion | Who arranges testing, inspections and records? | Handover checklist and required documents |
Add a due date against unresolved items. Ask the builder which decisions must be settled before signing, manufacture, site works and delivery. Keep dated replies with the quote instead of relying on a later conversation to fill the gaps.
The granny-flat cost guide helps assemble the full budget. This worksheet identifies who must price the missing service work; it supplies no installation allowance or national cost estimate.
Worked example: two quotes with different boundaries
Consider an illustrative owner comparing two prefab quotes for the same backyard. Quote A includes internal wiring and plumbing to labelled points on the module. Quote B includes those items plus defined connections to existing property services. Both mention “metering” without explaining the account arrangement.
The owner sends both suppliers the same site plan and worksheet. Supplier A is asked to identify the local work the owner must procure. Supplier B is asked to confirm its included route, assumptions about existing services and treatment of any required upgrade. Both are asked what “metering” means in their scope.
Next, the owner obtains provider confirmation about the intended billing arrangement and asks the relevant trades to price unresolved work. An allowance remains marked as an allowance until its scope and price are settled.
Only then can the owner compare the same completed outcome. A lower initial total may simply contain less work. This example is a comparison method, not a supplier quote or a prediction that an upgrade will be needed.
If rental is possible, keep charging questions separate
Tell the providers and your property adviser before settling the arrangement. Do not treat a meter reading, a building approval or a builder's inclusion as confirmation of what can be charged to a tenant.
Ask the relevant state tenancy authority which current rules apply to the intended arrangement. This guide does not provide a bill-splitting formula, determine tenancy compliance or recommend on-selling electricity.
Take the completed scope to your shortlist
Use the granny flats Australia hub and modular builder directory to find suppliers, then compare their answers using the granny-flat builder questions.
If you are also considering a compact prefab cabin, view Zinc Studio's profile. Zinc Studio has a featured commercial placement in this directory. Confirm the proposed product, intended use, service area and site-connection scope directly; the placement does not establish suitability for a granny-flat project.
Sources and limitations
The linked Hunter Water, Icon Water, Ausgrid and Energy Made Easy pages were checked on 15 September 2026. Their examples explain why project scope and billing need separate confirmation. Provider-specific arrangements must not be transferred to another service area.
General project-planning information only, not electrical, plumbing, tenancy or legal advice. Ask licensed trades and the relevant providers to confirm requirements for the address. Check proposed rental arrangements with the state tenancy authority and obtain professional advice where needed.