Let me get the legal bit out of the way first: in Australia, all electrical work must be done by a licensed electrician. That includes wiring your shed. It’s not a DIY job, and if you wire it yourself, your insurance is void, you can’t sell the property without rectifying it, and you might set the thing on fire. So don’t do it yourself.

But you absolutely should understand what’s involved before you call the sparky. Knowing what you need, asking the right questions, and having a plan saves you money (electricians work faster when the plan is clear) and ensures you end up with a setup that actually suits how you use the space.

I’ve had three sheds wired over the years across Brisbane. The first time, I had no idea what I needed and ended up with too few circuits and poorly placed outlets. Lesson learned.

Running Power to the Shed

The first decision is how to get electricity from your house to the shed. There are two main options.

Overhead Cable

A cable run from your house’s switchboard to the shed, supported on a catenary wire or run through conduit. This is usually the cheaper option because it avoids trenching.

Considerations: Minimum clearance requirements apply — generally 2.7 metres over non-trafficable areas and 5.5 metres over driveways. If your shed is close to the house, this is straightforward. If it’s at the back of a long yard, the span might be too long without intermediate support poles.

Underground Cable

Cable buried in conduit at a minimum depth of 300mm (500mm under driveways or trafficable areas) from the house to the shed. More expensive because of trenching, but cleaner looking and no overhead clearance issues.

I went underground for my current workshop. It cost about $800 more than overhead, but I didn’t want a cable spanning the length of the yard. The trench was done in half a day with a ditch witch — your electrician can usually organise this or recommend someone.

According to Energy Queensland’s regulations, all underground cable installations must use appropriately rated conduit and be buried to the correct depth for the cable type.

Sub-Main Cable Sizing

The cable running from the house to the shed needs to be sized for the expected load. This is where your electrician does the calculations, but as a rough guide:

• Light use (lights, a few power points, basic tools): 6mm² cable is usually sufficient
• Workshop with power tools: 10mm² cable handles most single-phase workshop loads
• Heavy machinery (welder, large compressor, dust collector running simultaneously): 16mm² or discuss three-phase with your electrician

Undersizing the sub-main is one of the most common mistakes. It costs barely more to run a larger cable now than it does to dig it up and replace it later.

Planning Your Shed Circuits

Before the electrician arrives, think about how you use (or plan to use) the space. Walk through the shed and think about where you’ll work, where you need light, and what equipment you’ll run.

Lighting Circuit

A dedicated circuit for lighting, separate from your power outlets. This means if you trip a power circuit (common with power tools), you’re not suddenly working in the dark.

How much light: Most workshops need about 500 lux at bench height for detailed work. As a rough guide, that’s about 15-20 watts of LED lighting per square metre of floor space. For a 6x3m shed (18m²), that’s 270-360 watts of LED — roughly six LED battens.

Placement: Lights directly above workbenches and power tool locations. I’ve got four LED battens running the length of the shed plus two positioned over my main workbench. No shadows where I’m actually working.

Switching: Consider multiple light switches — one at the door and one at your main work area. A single switch by the door is annoying when you’re at the back of the shed.

General Power Outlets

More is always better. Outlets are cheap during initial wiring and expensive to add later. My rule: wherever you think you need one outlet, put two.

Workbench area: At least four double power points along the back wall at bench height (about 1100mm from floor). This covers a drill press, grinder, charger, and whatever else you’ve got running.

Around the walls: Double power points every 2-3 metres around the perimeter, at standard 300mm height. You’ll use them for vacuums, fans, heaters, chargers, and tools you haven’t bought yet.

Ceiling outlet: One near the centre of the shed for a pendant fan, dust collector drop, or retractable cord reel. Easy to forget during planning.

Dedicated Circuits for Heavy Equipment

If you run equipment that draws significant current — table saws, welders, air compressors, dust collectors — these should have dedicated circuits. A table saw on a shared circuit with your bench grinder and a radio will trip the breaker regularly.

Talk to your electrician about your biggest power tools. Bring the nameplate data (amps rating) if you can. They’ll spec dedicated circuits and appropriately rated outlets.

Three-phase consideration: If you’re running serious machinery — a 3HP dust collector, a large welder, a big compressor — three-phase power might be worth considering. It’s more expensive to install (and three-phase supply isn’t available everywhere in Brisbane suburbia), but it runs large motors more efficiently and gives you more capacity. Worth asking about during planning even if you don’t need it now.

The Switchboard

Your shed needs its own sub-board (mini switchboard) with circuit breakers and RCDs (safety switches). This is typically mounted near the entry door inside the shed.

A basic workshop sub-board might have:

• Main switch (to isolate all power to the shed)
• RCD/safety switch (legally required)
• Lighting circuit breaker
• 2-3 general power circuit breakers
• 1-2 dedicated circuit breakers for heavy equipment

Having separate circuit breakers for different circuits means you can isolate specific areas for maintenance and a tripped breaker only affects one circuit, not the entire shed.

What It Costs

Pricing varies significantly by location, complexity, and distance from the house. Based on my experience in the Brisbane area:

• Basic setup (underground cable run, sub-board, lighting circuit, 4-6 power points): $2,500-$4,000
• Workshop setup (underground cable, sub-board, good lighting, 8-12 power points, 1-2 dedicated circuits): $4,000-$7,000
• Full workshop with three-phase (three-phase supply, comprehensive sub-board, extensive outlets, dedicated circuits): $7,000-$12,000+

Always get at least three quotes. Ask each electrician to break down the quote by materials and labour so you can compare properly. The range between quotes can be surprising — I once received quotes of $3,800 and $6,200 for essentially the same scope of work. I’ve worked with Team400 on projects where we approach estimation the same way — breaking scope into components and getting clear on what each piece costs before committing.

Getting It Right the First Time

Plan for future use. Run a bigger cable than you need right now. Add more outlets than you think you need. Include conduit runs that aren’t wired yet but give you pathways for future additions.

Think about dust. Workshop dust gets into everything. Ask for IP-rated outlets (dust and moisture protected) if you’re doing woodworking. Standard household outlets accumulate sawdust in the gaps and eventually become a hazard.

Consider exterior lighting and power. While the electrician is there, add a weatherproof outlet and a security light on the outside of the shed. The marginal cost of adding these during the initial wiring is minimal compared to a separate callout later.

Get a compliance certificate. Your electrician should provide a Certificate of Compliance for Electrical Work. Keep this — you’ll need it for insurance claims and property sales.

Good shed wiring is an investment you make once and benefit from for decades. Plan it well, communicate clearly with your electrician, and don’t cheap out on cable sizing or outlet numbers. Future you will be grateful.