The electrical fit-out is where most shed owners regret their original specification. The lighting was inadequate. The power points are in the wrong places. The circuit isn’t sized for the actual equipment being used. The retrofit work after the shed is finished is more expensive and more disruptive than getting it right the first time.

This is a working-tradie view of what’s worth specifying upfront and what’s safe to skip.

The basic question: how much shed will you actually use it as

The first question that determines everything else is how the shed will actually be used. The general-storage shed has very different electrical needs from the workshop shed, the home gym shed, or the granny flat shed.

A general-storage shed needs basic lighting, a couple of power points, and not much else. Investing in a complex electrical fit-out for a shed that will mainly hold the lawnmower and garden tools is overspending.

A workshop shed needs serious lighting, generous power points distributed appropriately, sufficient circuit capacity for tools and machinery, and possibly three-phase if you’re running larger equipment. Underspecifying here produces years of frustration.

A home gym shed needs reasonable lighting, audio/video power points, climate control circuits, and maybe charging points for fitness tech. The needs are specific but not extreme.

A granny flat shed needs everything a small dwelling needs and brings in regulatory requirements that add complexity and cost.

Be honest about which category your shed will actually fall into. Owners who are honest about realistic use specify appropriately. Owners who plan for fantasy use overspend on capability they don’t need.

Lighting

Shed lighting has been transformed by LED technology over the past decade. The current generation of LED tubes and panels produces serious light at modest power consumption.

For a workshop shed, the lighting target should be around 500 lux at the work surface. This is brighter than most owners expect. A shed with two strips of 4-foot LED tubes is generally too dim for fine work; a shed with multiple ceiling-mounted LED panels distributed properly is closer to right.

The colour temperature matters too. Cool white (5000K-6500K) is appropriate for workshop tasks where colour accuracy matters. Warm white (2700K-3000K) is more comfortable for general living spaces. Workshop spaces benefit from cool white; the warm white that’s comfortable in a kitchen is too dim-feeling in a workshop.

The placement matters as much as the quantity. Lights directly above the work area beat lights at the side. Lights with reasonable spacing beat one bright fixture in the centre. The shadows your own body casts when you’re working are visible on most light setups; the only fix is multiple light sources.

For sheds with high ceilings, high-bay LED fixtures are appropriate. These produce a lot of light and direct it downward effectively. They’re more expensive than tubes but suited to the geometry.

Power points

Power point quantity and placement is where most regrets happen.

The basic principle is more is better. Power points are cheap to specify during construction and expensive to add later. A shed with eight power points distributed thoughtfully will use them all. A shed with four will end up with extension leads everywhere.

The placement matters. Power points at the typical workbench height (around 1.2m off the floor) are useful for tools used at the bench. Power points lower down (300-600mm off the floor) are useful for floor-mounted equipment. Power points up higher (around 1.8m or above) are useful for fixed lighting and mounted devices.

For workshop sheds, dedicating specific circuits to specific equipment is worth the cost. The dust collector on its own circuit. The compressor on its own circuit. The tablesaw or major machinery on its own circuit. This avoids the situation where running two pieces of equipment trips the breaker.

The total circuit capacity should be sized for the realistic peak load, not for the average load. The compressor that draws 2000W when running plus the lighting plus the radio plus the phone charger plus whatever else is running adds up to circuit demands that consumer-grade circuits don’t always handle.

Three-phase or single-phase

The three-phase question is one of the bigger decisions. Three-phase opens the door to more capable workshop equipment — large compressors, professional welders, larger machine tools, certain woodworking equipment. It also adds substantial cost.

For most residential workshop sheds, single-phase is adequate. The hobbyist tools that run on single-phase are capable of doing serious work. The cost difference for three-phase is usually substantial.

For sheds where the owner is genuinely running serious commercial-grade equipment, three-phase is worth the cost. The equipment runs better on three-phase, the circuit loads are easier to manage, and the future flexibility is real.

The honest middle ground is to install single-phase but design the wiring run so that an upgrade to three-phase is straightforward later. The conduit and service-side capacity can be set up for three-phase even if the current installation uses single-phase. This is a relatively cheap option that preserves future flexibility.

Subsidiary considerations

Several smaller specifications add up to a meaningfully better shed.

Outdoor power points on the exterior of the shed. Useful for charging vehicles, running outdoor equipment, powering temporary lighting. Cheap to add at construction time, expensive to retrofit.

Data and network capability. Whether through wired ethernet or solid Wi-Fi coverage, the shed should be properly networked. Many modern uses depend on this — security cameras, building automation, internet-connected workshop tools, simply being able to make calls without going back to the house.

Switching for the lighting that supports actual use patterns. The simple “all lights on or all lights off” switch is inadequate for many uses. Multi-zone switching that lets you light the work area without lighting the whole shed is useful.

Emergency lighting if the shed is large enough or if the use is significant enough. A small battery-backed LED that comes on when the power fails is cheap and useful.

Surge protection on the supply. Modern workshop equipment is more sensitive to surges than the equipment of decades past. Surge protection at the supply is worth the cost.

The compliance dimension

Shed electrical work in Australia must be done by a licensed electrician. The DIY shortcuts that show up in old shed videos are not legal and not worth the risk.

The electrical work also needs to comply with the relevant standards (AS/NZS 3000 and related), which include specific requirements for shed electrical work. The licensed electrician will handle this.

Where the shed is intended for habitation (granny flat use), the requirements step up substantially. The electrical needs to meet residential standards, the inspection requirements are stricter, and the documentation needs to be complete. This is worth getting right; non-compliant work creates problems at sale time and creates liability if something goes wrong.

The fit-out timing

The right time to do the electrical work depends on the shed construction approach.

For traditional stick-frame or steel-frame construction, the rough-in (cabling, conduit, structural mounting points) happens after the frame is up and before the wall lining goes on. The fit-off (final connection of fixtures, power points, switches) happens after the lining is finished.

For prefab sheds, the timing depends on the manufacturer. Some prefabs come with provision for electrical conduit; others require post-installation routing through the structure. Working with the manufacturer’s specifications is much easier than fighting them.

The site work — connecting the shed to the main supply, running underground feeders, installing the meter or sub-board — needs to be planned alongside the shed construction. A shed that’s structurally complete but has no power because the supply hasn’t been organised is a frustrating outcome.

What I’d actually specify

For a serious workshop shed, my standard specification would include:

LED lighting at 500+ lux at work surfaces, distributed in zones with separate switching.

At least eight power points distributed at multiple heights.

Dedicated circuits for major equipment (compressor, dust collector, primary machinery).

Outdoor power points.

Data/network connectivity.

Surge protection at the supply.

Wiring sized to allow future upgrade to three-phase if not initially specified.

These specifications produce a shed that works well for years and accommodates use changes that aren’t fully predictable at construction time. The cost is meaningful but recoverable through the use the shed actually gets. The shortcuts that owners regret are usually on lighting quantity, power point quantity, and circuit capacity. Don’t take those shortcuts. The rest of the electrical decisions are within reasonable margins of error.