Connecting Power to a Townhouse or Multi Dwelling Development: Scaling Beyond a Duplex

How does a townhouse or multi dwelling development get power connected when there are more than two homes on the one block? Each dwelling is treated as its own separately metered installation under SIRNSW Clause 4.13, supplied through shared infrastructure such as an MDC (Master Distribution Centre) or a common switchboard, with the developer's electrical contractor coordinating the distributor application early because larger multiple installation developments can trigger longer lead times than a standard home connection.

⚡ Quick Answers: Multi Dwelling Power Connections

• Is this the same as a duplex connection? The underlying rule is the same (SIRNSW Clause 4.13, Multiple Installations), but three or more dwellings need the MDC and submain arrangement properly scaled, not just duplicated from a two unit setup.
• Who coordinates the connection application? Your Level 2 ASP, ideally engaged early, since Clause 4.13 specifically tells larger developments to contact the distributor and Metering Coordinator as soon as possible.
• Does each unit get its own meter? Yes, the rules require supply to each separately metered portion of the installation from a single point of common coupling.
• What happens to the submain cupboards or risers? They must be sealed and clearly, permanently labelled so each occupancy is identifiable, and unmetered submains need lockable or sealable access.
• Could this end up as an embedded network instead? Sometimes, see our explainer on embedded networks for when a development goes down that path instead of individual retail connections.

1. Beyond the duplex: what actually changes at three or more units

Our own guide to two private poles and an MDC for a duplex or dual occupancy build covers exactly two dwellings sharing a subdivided block. A townhouse row or a small multi dwelling development of three, four or more units is governed by the same SIRNSW Clause 4.13 principle, multiple residential installations including a number of single domestic installations, but the practical arrangement has to scale. Instead of two MDC ways you might need four, six or more, the submain cable run from the point of attachment or pit has to be sized for every unit's combined demand, and the main switchboard enclosure needs enough physical space and heat dissipation clearance for that many sets of service equipment sitting side by side.

2. Engage the Level 2 ASP before the civil works start

SIRNSW Clause 4.13 is explicit on this point: for large multiple installation developments, contact the electricity distributor and Metering Coordinator as early as possible to prevent delays for connection of electricity. On a townhouse project this usually means well before slab, because the underground conduit routes, pit locations and MDC position all need to be agreed with the network before trenching happens, not after. A late engagement is one of the most common reasons a near finished development sits waiting on power for weeks.

3. Sizing the shared infrastructure

Every dwelling gets its own maximum demand calculation under AS/NZS 3000 Appendix C, the same method used for a single home, then those figures are combined (with appropriate diversity where it genuinely applies) to size the submain cable feeding the MDC and the capacity requested from the distributor. Getting this wrong in either direction causes real problems: undersize it and later owners can't add an EV charger or a heat pump without a capital works job to the shared submain; oversize it without reason and the development pays for network capacity nobody uses.

4. Metering, sealing and labelling requirements

SIRNSW Clause 4.13 sets out specific obligations once the shared equipment is in: unmetered submains must be sealed or locked, with the customer providing facilities for this and responsible for the cost; service equipment and meter panels must be clearly and permanently labelled to identify which occupancy each one serves; and adequate space must be maintained around all service equipment for safe operation and heat dissipation. These aren't box ticking details, a poorly labelled MDC is how the wrong unit gets disconnected during a fault years after the builder has moved on.

5. Private poles, overhead or underground, and the MDC

Depending on the site layout, a multi dwelling development might need a new private power pole, upgraded underground service mains, or simply an upgrade to the existing overhead service feeding the block. Where the layout genuinely needs more than one point of attachment, the coordination logic from our two pole duplex guide still applies, just scaled up: every supply point feeding the same development still has to tie back to the one MDC arrangement rather than becoming disconnected, unapproved parallel supplies.

6. When it becomes an embedded network instead

On some larger developments, rather than each unit holding its own retail electricity contract through the shared metering arrangement above, the developer or owners corporation sets up an embedded network: one bulk connection to the site with sub metering and a parent/child retail relationship behind it. This is a different regulatory path again, governed by the Australian Energy Regulator's exemption framework rather than SIRNSW metering rules alone. Our embedded network explainer covers why some residents end up unable to choose their own retailer under this model and what it means day to day.

Why it's Level 2 ASP work

Applying for multiple simultaneous connections, designing a shared MDC arrangement, and sizing submains against a combined maximum demand all sit on the network side of the installation, which is Level 2 electrician and Accredited Service Provider territory, not standard licensed electrical work. Builders who leave this until late in the program are the ones who end up with a finished townhouse row still waiting on a connection date.

How High Demand Electrical helps

We're one of Sydney's most trusted Level 2 ASPs for builder facing multi dwelling connections, from a straightforward duplex through to larger townhouse rows needing a properly scaled MDC. We get involved early, lodge the distributor application with a genuine load schedule attached, and make sure every submain, meter panel and piece of shared service equipment is labelled and sealed the way SIRNSW actually requires, servicing developments across Sydney's growth corridors and established suburbs alike.

Multi Dwelling Power Connection FAQs (Sydney)

How many dwellings before this stops being a simple duplex connection?

There's no hard number in the Rules themselves, but in practice three or more dwellings is where a genuinely scaled MDC design, rather than a straight copy of a two unit layout, becomes necessary.

Does strata come into this for a townhouse development?

Often yes, once titles are issued. See our strata switchboard capacity guide for how common property infrastructure gets managed once an owners corporation exists.

Can an existing single supply be split into separate connections later?

Sometimes, though it's far more straightforward to design the separately metered supply in from the start. Retrofitting individual connections into an existing shared supply is a bigger job.

Which network applies, Ausgrid or Endeavour Energy?

Check your network area in seconds with our postcode checker, since the application process and lead times differ between distributors.

If you're building a townhouse row, a small multi dwelling development or anything beyond a straightforward duplex, talk to us before the trenching starts. Get a Level 3 design quote from High Demand Electrical or call 0402 559 777. A site assessment is needed before scope and pricing can be confirmed.