New Build Electrical Checklist: What to Lock In Before the Slab Is Poured

What electrical decisions need locking in before your slab is poured? Seven: the supply size and phase count, the underground service route, where the meter and switchboard live, a conduit spine for future cabling, spare capacity on the board, provisions for EV, solar and battery, and the network connection application itself. Every one of them is cheap while the site is open ground and painful to change once concrete and walls exist.

⚡ Quick Answers: new build electrical in Sydney

• When should the electrical plan be settled? At design stage, before the slab. Trenching, conduit and supply sizing all depend on decisions that predate the pour.
• Single phase or three phase? Decide once, now. Bringing three phase in during the build costs a fraction of retrofitting it later.
• Will the connection be underground? In new estates, yes, supply typically arrives underground from a pit or pillar, and the trench needs to happen while the site is open.
• Who applies to the network? A Level 2 ASP can lodge and manage the connection application with Ausgrid or Endeavour Energy on your behalf.
• What gets forgotten most? Conduits and draw wires. Empty pipe laid before the slab makes every future cable a pull instead of a dig.

1. Decide the supply size and phase count first

Everything downstream is sized from this one decision. A modern build with ducted air conditioning, induction cooking, EV charging and a pool is a very different electrical proposition from the homes most standards assumed a generation ago. Our single vs three phase decision guide walks through the call, and what changes with three phase shows what you get for it.

The build is the one moment the price gap is small. The trench is open, the switchboard is new and the metering is being set up regardless, so specifying three phase now avoids an entire upgrade project later.

2. Lock the service route while the ground is open

New subdivisions are supplied underground, so your connection will run from the street pit or pillar to the house in a trench. The route, depth and conduit have to meet the network's rules, and the smart time to dig is before landscaping, driveways and paths go down. Our underground conversion guide covers the mechanics, and every dig starts with a BYDA search even on a bare block, because service trenches for water, sewer and comms arrive early too.

3. Put the meter and switchboard where they belong

Meter positions are not a free choice: the distributor needs safe, unobstructed access, and your electrician needs the board somewhere sensible for the home's cable runs. Moving a meter box after handover is a genuine project. Settle the position on the plans, not on site, and keep future needs like a second board or battery wall in mind when the location is chosen.

4. Lay a conduit spine before the slab

The cheapest thing you will ever install is empty conduit under a slab. A spine of oversized conduit with draw wires, from the board to the garage, the roof space and the rear of the block, turns every future job into a cable pull. It is the same walls-open logic as our renovation decisions guide, except on a new build the marginal cost is even smaller.

5. Size the switchboard for the home you will have

Spare ways cost almost nothing at build time. A board with generous spare capacity absorbs the future EV circuit, the pool, the battery and whatever comes after without a board upgrade. Skimp here and you are reading our switchboard upgrade guide in five years.

6. Provision for EV, solar and battery now

You do not need to buy any of it yet. You need the provisions: a conduit run and board space for the EV circuit, the pre-wiring that makes a home solar ready rather than solar retrofitted, and a sensible wall and switchboard allowance from our battery ready checklist. Detached garages and granny flats deserve a thought here too: a properly fed sub board beats a tangle of long individual circuits.

7. Lodge the connection application early

The physical connection cannot happen until the network paperwork is done, and approval timeframes are outside everyone's control. Which network you are on shapes the process, so check your network area in seconds with our postcode checker, and see our comparison of connection timeframes for new builds. Secondary dwellings have their own path, covered in the granny flat connection guide.

Why it's Level 2 ASP work

The service line from the street to your meter, the consumer mains and the energisation of a new connection are network connected work that only a Level 2 Accredited Service Provider can perform in NSW. A builder's electrician wires the house; the connection itself needs an ASP. High Demand Electrical is accredited on both the Ausgrid and Endeavour Energy networks and handles consumer mains and underground service work daily.

How High Demand Electrical helps

Bring us in at design stage and we take the checklist off your plate: supply sizing and the phase decision, the connection application, the trench and conduit spec, metering, and coordination with your builder's sparky so the house wiring and the connection land together. One team, one application, no surprises at energisation.

New build electrical FAQs (Sydney)

When should a Level 2 electrician get involved in a new build?

At design stage, before the slab. That is when supply size, service route and meter position are still free choices rather than variations.

Can I add three phase later if I skip it now?

Yes, but as a standalone upgrade project with its own network application, mains work and switchboard changes. During the build it is a specification line. Afterwards it is a retrofit.

Who lodges the connection application, the builder or me?

Either can, but in practice a Level 2 ASP manages it best because the application, the service work and the certification are all theirs to complete. We do this routinely for owners and builders alike.

Does a granny flat on the same block need its own connection?

Usually it shares the main connection and runs from a sub board, though metering arrangements vary. The granny flat guide covers the options.

Building soon?

Get a new connection quote or call 0402 559 777 before your slab date is set. Every job starts with a site assessment before scope and pricing are confirmed.