How to wire a shed for lights and power safely

⚡ Safe shed wiring guide for lights and power in Australia

What are the key considerations for safely wiring a shed in Australia?

Wiring a shed for lighting and power involves planning the load, selecting the correct cable route and protection devices, and ensuring the installation complies with AS/NZS 3000 Wiring Rules and local supply requirements. For most Australian sheds, this means a subcircuit or submain from the house switchboard, suitable underground or above-ground cable protection, correct earthing, and RCD protection for all final subcircuits.

Electrical work in Australia must be performed by a licensed electrician. This guide is for understanding the process and selecting the right tools and materials.

What skill level is required for wiring a shed for lights and power in Australia?

Advanced — Estimated time: 1-2 days for planning and rough-in, plus testing and certification by a licensed electrician

What essential tools are needed for wiring a shed for lights and power in Australia?

What specific materials are required for wiring a shed in Australia?

Safety Requirements

Step-by-Step Guide

Step 1: Plan the shed layout and electrical load

Start by deciding how the shed will be used: storage, workshop, home office or mixed use. This determines the number of lights, power points and any high-load equipment such as welders, compressors, fridges or EV charging equipment.

Mark the position of:

Calculate the likely load so the correct circuit arrangement can be selected. A basic storage shed may only need one lighting circuit and one power circuit, while a workshop may justify a small sub-board with separate circuits.

💡 Leave room for future expansion. It is often worth installing an extra conduit or a slightly larger submain during the first fit-out.

Step 2: Decide whether the shed needs a single circuit or a sub-board

For a small shed close to the house, a single dedicated circuit may be enough. For larger sheds, long cable runs, or multiple loads, a sub-board in the shed is often the better option.

A shed sub-board is commonly the best choice when:

Typical cable sizes for discussion with your electrician may include 4mm², 6mm² or 10mm² TPS for the submain, but exact sizing must be based on demand, installation method, fault current and voltage drop calculations under AS/NZS 3000.

Step 3: Choose the cable route and wiring method

There are usually two main routes to a detached shed:

This is the neatest and most common solution. Cable is installed in heavy-duty conduit with appropriate burial depth and mechanical protection. Warning tape should be installed above the conduit in the trench.

This may be possible between structures using catenary support systems or suitable protected wiring methods, but clearance, mechanical support and exposure must be carefully assessed.

Inside the shed, cables are typically run:

In metal sheds, extra care is needed around sharp edges, gland entries and earthing/bonding requirements.

Step 4: Confirm protection devices and switchboard capacity

Check whether the house switchboard has:

For most modern installations, using RCBOs provides both overload and residual current protection per circuit. If the shed has its own sub-board, the arrangement must be coordinated so nuisance tripping and discrimination issues are minimised.

This is also the stage to confirm whether surge protection is worthwhile, especially for home office sheds or workshops with expensive tools.

Step 5: Install the submain or supply cable to the shed

Once the route and cable size are confirmed, the supply cable is run from the main switchboard to the shed.

For underground runs:

For above-ground runs:

Where the shed is metal-clad, all entries should be bushed or glanded to prevent cable damage.

Step 6: Install the shed sub-board or final circuit termination

If a sub-board is used, mount it in a dry, accessible location inside the shed. Keep it away from likely impact zones, excessive dust, or direct weather.

The sub-board may contain:

If only one final circuit is being supplied, terminate the circuit at the first accessory or isolation point in accordance with the design. Labelling at the main switchboard and shed is important so the supply can be identified quickly.

Step 7: Rough-in lighting and power circuits

Run the internal circuits to the planned locations.

Typical arrangements:

Mount power points at practical heights. In workshops, higher GPOs above benches reduce lead clutter. Space outlets to avoid over-reliance on power boards.

For lighting:

In exposed or unfinished sheds, surface conduit is often the cleanest and most durable method. It also makes future alterations easier.

Step 8: Install switches, lights and socket-outlets

Fit accessories once the rough-in is complete.

For lights:

For power:

Check that all terminations are firm, conductors are fully inserted, and no copper is exposed beyond terminals.

Step 9: Earthing, bonding and mechanical protection checks

Before testing, confirm:

Metal sheds can present extra fault risks if earthing or bonding is poor. This step is critical for shock protection.

Step 10: Test, verify and label the installation

The completed installation must be tested by a licensed electrician before energisation.

Testing typically includes:

All circuits should be clearly labelled at the switchboard or sub-board, for example:

This helps with future maintenance and emergency isolation.

Step 11: Energise and check real-world use

After certification and energisation, confirm the installation performs as intended:

💡 A final walk-through at night is useful to check lighting levels, shadows and switch convenience.

Common Mistakes to Avoid

Pro Tips

Recommended Tools

⚠️ Safety

🔒 Licensing

Electrical wiring, circuit installation, switchboard alterations, and final connections in Australia require a licensed electrician. State regulators include NSW Fair Trading, VIC ESV, QLD ESO, and WA EnergySafety. Compliance with AS/NZS 3000 and applicable service and installation rules is mandatory.