DIY Laws by State: What Aussies Can (and Can’t) Legally Do at Home

By the I Do It Yourself team — Ash, Tomo, Mick, Steve and Cal.

The single most expensive mistake we see Aussie homeowners make isn’t a bodged tile job or a dodgy paint finish — it’s unlicensed work that voids their home insurance. Every state has its own rules about what a homeowner can legally do at home, and the lines don’t always sit where you’d expect. Plumbing law in Queensland isn’t the same as plumbing law in Victoria. Electrical law in WA is slightly more relaxed than in NSW. Waterproofing in SA has different certification requirements than in QLD. And almost every state has hardened up its rules in the last decade.

This is the guide we wish every new homeowner read before their first weekend reno. It covers what you can legally touch in each state and territory, why the rules exist, and what happens when an insurer or a conveyancer finds out the bathroom rough-in was done by your brother-in-law. The short version: it’s almost never worth saving $1,500 on unlicensed work when it could cost you $40,000 in an insurance dispute or kill a sale at the inspection stage.

Why this matters — insurance, conveyancing, and resale

Three things ride on whether your DIY work was legal: your home and contents insurance, your eventual sale of the property, and your own liability if somebody gets hurt. We’ll take them one by one.

Insurance: every standard PDS in Australia contains a clause that excludes claims arising from unlicensed building, electrical, plumbing, gas or waterproofing work. That clause is rarely triggered in normal claims — but the moment something serious happens (fire, flood, electrocution), the insurer’s loss assessor pulls the certificates of compliance for the relevant trades, and if there aren’t any, your $500,000 fire claim becomes a $0 claim. We’ve seen it happen. Twice in the last five years.

Conveyancing: when you sell, your conveyancer issues a Section 32 (VIC) or Contract for Sale (NSW/QLD/etc) that asks specifically about building work, electrical work, plumbing work and pool fencing — and whether each was done with the relevant certificates. Buyers’ solicitors are increasingly picky about this, and unanswered or “unknown” tends to kill a sale or trigger a price reduction at the worst possible time.

Liability: if a future occupant gets hurt because of work you did unlicensed, you can be personally liable — and there’s no insurance backing you up. That’s a long-tail risk people forget about because it doesn’t bite for years.

Phase 1: Electrical work — what’s legal in each state

Ash here. Electricity doesn’t care about your weekend plans, and the law in every Australian state takes the same view. The umbrella standard is AS/NZS 3000 (the wiring rules), and on top of that each state has its own Electrical Safety Act and licensing regime. I get this question alot — “but in [state] I heard you can replace a light fitting yourself” — and the honest answer is, no, almost nowhere can you legally replace fixed wiring, and the exceptions are narrower than the internet would have you believe.

Here’s the rundown:

NSW: Licensed electrical work covers any fixed wiring. Homeowners can plug things in, replace plug tops on existing flex, and reset breakers. That’s it. Replacing a powerpoint, switch or light fitting is licensed work under the Home Building Act and the Electrical Safety Act 2018.
VIC: Almost identical to NSW. Energy Safe Victoria enforces a strict line — anything past the plug top is licensed. The penalty for unlicensed work is up to $40,000 for an individual.
QLD: Same line as NSW/VIC. Worth noting QLD has the most active enforcement — the Electrical Safety Office publishes monthly prosecutions, including against homeowners who DIY’d a powerpoint.
SA: Restricted electrical work licensing is enforced by the Office of the Technical Regulator. Homeowners cannot do any fixed wiring. Period.
WA: Slightly more permissive on the books — under the Electricity (Licensing) Regulations 1991 a “regular occupier” can do limited work on their own dwelling, BUT it must be inspected and certified by a licensed inspector. In practice, almost nobody bothers because the inspection costs more than just paying a sparky.
TAS: Same as NSW/VIC/QLD — licensed only for fixed wiring.
ACT: Strict — Access Canberra enforces the licensing regime and there’s effectively no homeowner exemption.
NT: Same — Power and Water and the Electrical Workers and Contractors Licensing Board enforce a hard line.

The common myth I hear is “I can replace a light fitting if it’s the same wattage.” That’s wrong everywhere. The myth comes from a UK regulation that doesn’t apply here. In Australia, a hardwired light fitting is fixed wiring, and fixed wiring is licensed-only — even if you’re swapping like-for-like. The only exception is a plug-in pendant or a plug-in lamp, where there’s a flex and a plug top.

What you absolutely shouldn’t do, in any state: work inside a switchboard, run new cable in the wall or roof cavity, replace a powerpoint, replace a switch, replace a hardwired downlight, or terminate any cable to a hardwired appliance. The sparky’s call-out fee for a powerpoint swap is around $180–$280. The recieved cost of getting it wrong, if you’re unlucky, is a fatal arc fault and a voided insurance policy.

Phase 2: Plumbing work — restricted versus unrestricted

Tomo here. Look mate, the rules exist for a reason. The reason is that bad plumbing work doesn’t just cost money — it contaminates drinking water, floods walls, sends sewage into living spaces, and the leaks rot structural timber for years before anybody notices. Every state’s plumbing regulator has a list of “restricted” work (licensed plumbers only) and “unrestricted” work (homeowner can do it). The lists are similar but not identical, and the unrestricted list is shorter than most people expect.

Unrestricted work that a homeowner can legally do in most states:

Replace a tap washer or O-ring on an existing tap
Replace a toilet seat
Replace a shower head or hand-held rose where it screws onto an existing connection
Replace the inlet hose on a washing machine (where the hose has a screw connector)
Clear a blocked drain using a plunger or a hand-snake
Replace a flexible hose under a sink in some states (NOT QLD — see below)

Restricted work that requires a licensed plumber in every state:

Anything inside the wall or under the slab
Replacing or relocating a mixer tap (in most states — TAS and SA allow some flexibility)
Hot water unit installation, replacement or relocation
Installing or replacing a toilet pan (yes, even like-for-like)
Connecting to mains water or to the sewer
Backflow prevention device installation
Anything connected to gas (covered separately in phase 5)

Then there’s WaterMark. Every plumbing fitting that connects to the potable water supply in Australia must carry a WaterMark certification — that’s how we know the brass alloy doesn’t leach lead, the rubber seals don’t perish in chlorinated water, and the mechanism doesn’t backflow into the mains. If you DIY a fitting that isn’t WaterMark certified, you’ve broken the Plumbing Code of Australia regardless of which state you’re in. That cheap mixer tap from an overseas online store? Almost certainly not WaterMark — and you can spot it because there’s no logo stamped on the body.

State-by-state quirks:

QLD: The strictest state. Even flexi hose replacement under a sink is restricted work in QLD if it’s connected to the mains. Pay a plumber.
NSW: Fair Trading enforces licensing. Restricted plumbing penalty is up to $22,000 for an individual.
VIC: Victorian Building Authority. Same hard line on anything past the isolation valve.
SA: Office of the Technical Regulator. Slightly more permissive on tap replacement where the fitting type doesn’t change.
WA: Building Commission. Hard line on hot water units and mains connections.
TAS: CBOS. Slightly more permissive on minor work but still licensed for anything inside the wall.
ACT: Access Canberra. Strict.
NT: Plumbers and Drainers Licensing Board. Strict, same approach as QLD.

I’ve seen this go wrong more times than I can count — homeowner replaces a mixer tap, the cartridge is from the same brand as the original but the body geometry has changed slightly, the seal leaks at 2 am, the cabinet under the sink fills up, and the kitchen floor is a write-off by morning. Cheaper to do once.

Phase 3: Structural, load-bearing and footings work

Mick here. Right, here’s the thing — most of what you’d call “structural” in a house is governed by the National Construction Code (NCC), which is a national document that the states each adopt with minor amendments. The NCC, plus your state’s Building Act and the local council’s planning scheme, decide when you need a building permit, when you need a private certifier, and when you can just get on with it.

What you can almost always do without a permit, in any state:

Hang a TV, mirror or curtain rail on plasterboard or brick veneer (it’s just fixings, not structural)
Patch a plasterboard hole (any size — you’re repairing, not changing)
Replace internal doors and door furniture
Replace a fly screen, an internal blind or a curtain
Repaint anything inside the house
Install a non-structural shelf or built-in
Replace floor coverings (carpet, vinyl, laminate, engineered timber)

What you definately need a building permit for, in most states:

Removing a load-bearing wall (always — even partly)
Adding or moving a window or external door
Building a deck above a certain height (varies by state — typically anything above 1 m off the ground)
Building a carport, garage or substantial shed (>10 m² in most states)
Pool fencing (always — it’s a child safety issue)
Anything that changes the building footprint or the BCA classification
Footings work, retaining walls over a certain height (typically 1 m)

The big one is load-bearing walls. The mistake we see — and the ones that end up in newspapers — is somebody who’s renovated their kitchen, decides to “open up” the wall between kitchen and lounge, swings the sledgehammer on a Saturday afternoon and pulls down a load-bearing wall without a temporary prop, then watches the ceiling sag. Or worse, gets away with it for two years and the ceiling cracks slowly until a tradie spots it during a routine job. Always — always — get a structural engineer’s report before you touch any internal wall you’re not 100% sure is non-load-bearing. The report costs $400–$800 and tells you exactly what’s needed.

A useful rule of thumb (not a substitute for the engineer): if the wall runs perpendicular to the roof joists or floor joists above, it’s probably load-bearing. If it runs parallel, it’s probably not. But “probably” doesn’t cut it — get the report. The other rule: any wall in the centre of a house that’s been there since construction is more likely than not to be doing something structural, even if it looks decorative.

Phase 4: Wet-area waterproofing under AS 3740

Steve here. Twenty years on the tools and I still see DIY waterproofing fail. The standard is AS 3740-2021 (“Waterproofing of domestic wet areas”) and it’s been the binding national standard since 2010, with state Acts adding the licensing teeth on top. The short version: in NSW, QLD and VIC, any work that breaks the existing waterproof membrane in a bathroom, ensuite, laundry or external balcony has to be done by a licensed waterproofer who issues a certificate of compliance. SA and WA are technically more permissive on paper but the insurance reality makes it functionally the same.

What the membrane does: it sits under the tiles, runs up the walls 1800 mm in the shower, 150 mm at every wet-edge, with a 150 mm upturn at every internal corner. It is what stops water that gets past the grout (and water always gets past the grout, eventually) from rotting the floor joists and the wall framing. Get it wrong, the leak doesn’t show up for 12–24 months, and by the time you see it on the ceiling below, the structural timber is gone.

What you can DIY in a wet area without a licence (membrane intact):

Replace silicone in an internal corner (re-bead, don’t re-membrane)
Regrout existing tiles
Replace tap washers and cartridges (where permitted by plumbing law — see phase 2)
Replace a vanity onto pre-existing plumbing
Replace a toilet seat
Clean and seal grout
Replace a shower screen door or fixed panel (where the screen doesn’t penetrate the membrane)

What requires a licensed waterproofer:

Any new bathroom build
Pulling tiles off and replacing them in a wet area
Re-doing the floor falls
Installing a new floor waste or hob
Any membrane repair after a leak

The certificate that the waterproofer issues stays with the property and is asked for at conveyancing. If you’ve waterproofed your own bathroom without the cert, the buyer’s solicitor will either ask for a discount or walk away. Hill’s water down here is hard, so we see a lot of premature failures from poorly-mixed membrane — pay the $1,500–$2,500 for a licensed job and sleep at night.

Phase 5: Gas, fixed appliances and asbestos

Cal here. Quick yarn on the three categories of work that are nationally licensed-only, no exceptions, no homeowner permitted work whatsoever — gas, asbestos, and certain fixed appliance disconnects.

Gas: every state requires a licensed gasfitter for any gas work. That includes disconnecting an old gas cooktop or oven before you replace it with electric. It includes shifting a gas heater. It includes anything you do upstream of an appliance and downstream of the meter. The penalty in QLD alone is up to $80,000 for an individual doing unlicensed gas work — and there’s a reason. Gas leaks accumulate in cavities and the first sign of an unlicensed job is usually an explosion. There is no “I’ll just turn it off and disconnect the line myself” — call a gasfitter, $150–$280 for a disconnect.

Asbestos: under the Work Health and Safety Regulations (national framework, state-adopted), homeowners can technically remove up to 10 m² of bonded (non-friable) asbestos themselves — but every state strongly recommends licensed removal even for small quantities, and any friable asbestos at any quantity is licensed-only. The cost of a licensed removalist for a small bonded job is around $800–$2,000 — cheap compared to the lung disease 25 years later. The pre-1990 housing stock in Australia is full of asbestos: vinyl floor tiles, eaves sheeting, cement sheet behind bathroom tiles, fence panels, garage roofs, water pipes. Always test before you cut.

Fixed appliances: any appliance hardwired into the electrical or plumbing system needs a licensed sparky or plumber to disconnect and reconnect. That includes ovens, cooktops, dishwashers (where hardwired), rangehoods (where hardwired), built-in heaters and air conditioners. The exception is anything with a plug top and a flex — that, you can unplug yourself. A plug-in dishwasher? Fine. A hardwired one? Sparky.

The bottom line on this whole guide: the legal lines exist because the consequences of getting it wrong are big, slow, and often invisible. We’ve seen every one of these go wrong in the field. Save your DIY effort for the work that’s legally yours to do — patching, painting, tiling, gardening, cleaning, assembling, hanging, replacing-like-for-like within the unrestricted lists — and pay a licensed trade for the rest. The total tradie spend on a typical homeowner-managed reno is usually 20–30% of the total budget. Worth every cent.

The team’s verdict

If you take three things from this guide: one, every state has its own licensing regime but the broad lines are similar — electrical past the plug top, plumbing past the isolation valve, waterproofing past the membrane, all licensed in all states. Two, the cost of unlicensed work isn’t the fine — it’s the voided insurance and the killed sale years later. Three, when in doubt, ring your state regulator and ask. They’d rather answer the phone than prosecute.

Bookmark this guide, share it with anyone starting a renovation, and the next time someone tells you they’re “just going to swap the powerpoint themselves to save $200”, show them the QLD prosecutions page.

FAQs

If I bought my house with unlicensed work already done, am I liable? You inherit the consequences (voided insurance on that work, conveyancing issues at next sale) but not the original offence. Best practice is to get any suspect work re-inspected and certified by the relevant licensed trade — and use it as a price negotiation point if you spot it before settlement.

What if my insurer doesn’t ask about licensing at claim time? They almost always do, especially on claims over $20,000. The loss assessor will request certificates of compliance for relevant trades and the local council’s records of any permits.

Can I do work on my own investment property? Same rules apply — the licensing regime doesn’t distinguish between owner-occupier and investor. If anything, investors carry MORE liability because tenants have stronger legal protections.

How do I find a licensed tradie I can trust? Start with the state regulator’s online licence search (Fair Trading NSW, VBA Victoria, QBCC Queensland, etc) — check the licence is current. Then ask for references from recent jobs, and ask for a copy of the certificate of compliance for a recent similar job.

What if I get caught doing unlicensed work? Penalties vary by state but range from $5,000 to $80,000 for individuals, plus the cost of having the work re-done and certified, plus any insurance claim that gets voided, plus any conveyancing complication at next sale. The fine is the small part.

Got a project we should clarify the legal status of? Tell us.