What it costs to replace a kitchen sink in Australia, and why it's a licensed plumber job
Changing a kitchen sink involves the water supply, the drainage, and sometimes the benchtop. Here's what the work actually involves, what it costs in 2026, and how to choose a sink that won't disappoint.
A kitchen sink is the most-used fixture in your home. Replacing one is also one of the most-quoted residential plumbing jobs in Australia. The price range is huge because what looks like “swap one sink for another” almost never is.
This article explains what’s involved, what it costs, and how to choose a sink, not how to do it yourself. Sink replacement is licensed plumbing work in every Australian state because it touches the water supply and the drainage.
What the job actually involves
A typical kitchen sink replacement runs through:
- Isolating the water supply, the under-sink stop valves, or the bathroom/kitchen stop if no isolation
- Removing the existing taps or mixer, disconnecting the supply flexibles, removing the fixing nut from underneath
- Disconnecting the drainage, unscrewing the P-trap, removing the basket waste
- Removing the old sink, usually clipped from underneath, sometimes siliconed in
- Cleaning the cutout, old silicone, putty, and grime removed
- Testing the new sink fits the cutout, top-mounts hide minor variation, undermounts don’t
- Fitting the new sink, with new waste, plumber’s putty or silicone, fixing clips
- Re-connecting the drainage, new P-trap if old one was deteriorating
- Fitting the taps / mixer, new supply flexibles, fixing the mixer body, sealing
- Pressure testing and leak checking
A licensed plumber does the lot. They’ll also know whether the existing P-trap, stop valves, and supply flexibles need replacing, they often do, especially if the old kit is more than 10 years old.
Why this isn’t a DIY job in Australia
Every step that touches the water supply or drainage is licensed work. The reasons:
- Pressurised water behind your kitchen wall can flood your house in minutes if a fitting fails
- Drainage connections must be sealed properly or sewer gases come up through the cabinet
- Compliance certificates are required at sale in NSW, VIC, QLD; unlicensed work invalidates the title
- Home insurance generally excludes damage caused by unlicensed plumbing, the savings on labour can cost five figures if a fitting fails
A licensed plumber costs $80–$250/hour and will do the job in 2–3 hours for a straight swap.
2026 cost ranges
Straight sink swap (existing taps and cutout work)
| Item | AUD range |
|---|---|
| New sink (basic stainless single bowl) | $150–$300 |
| New sink (quality double bowl stainless) | $300–$700 |
| New sink (granite composite or fireclay) | $500–$1,500 |
| Designer / oversized sink | $1,000–$3,500+ |
| Labour (plumber, 2–3 hours) | $350–$700 |
| New supply flexibles | $30–$60 |
| New P-trap and waste | $40–$90 |
| Typical total | $600–$1,500 |
With new mixer / taps
Add $80–$800 for the tap or mixer itself, plus 1 hour labour.
With benchtop modification
If the new sink doesn’t fit the existing cutout, different size, different mount type, you’ll need either:
- Cutout adjustment by a stonemason/benchtop installer (~$200–$600 for laminate, $400–$1,200 for stone)
- Full benchtop replacement (~$1,500–$5,000+ for stone)
Plus the plumber comes back when the benchtop is ready.
Total scenarios
| Scenario | Realistic total (AUD) |
|---|---|
| Like-for-like swap, basic stainless sink, same taps | $500–$900 |
| New sink + new mixer, same cutout | $750–$1,500 |
| New sink, new mixer, cutout adjustment | $1,100–$2,200 |
| Sink + full benchtop replacement (stone) | $3,000–$8,000+ |
| Sink as part of kitchen renovation | Included in reno cost |
Choosing the sink
The two big questions:
Top-mount or undermount?
- Top-mount (drop-in): rim sits on top of the benchtop. Cheaper, easier to install, suits laminate. Lip catches crumbs.
- Undermount: sink fixed from below; benchtop edge is the only thing visible. Looks premium. Requires solid benchtop (stone, solid timber, engineered stone). Don’t fit to laminate, water gets to the chipboard core.
Single bowl, double bowl, or 1.5?
- Single bowl, large, fits big pots, less divider faffing
- Double bowl, traditional, two equal sinks, divides washing and drying
- 1.5 bowl, one large sink + one small sink. Australian favourite.
Material:
- Stainless steel, most common, durable, dents and scratches
- Granite composite, premium feel, chip-resistant, more expensive
- Fireclay / ceramic, premium farmhouse style, heavy, can chip from dropped pots
- Solid surface, integrated with benchtop, no joints
Hiring a plumber, what to verify
- Licence number and state, verify on the regulator’s online register
- Public liability insurance, $5M minimum, $10M ideally
- Quote includes: sink removal, new waste, new flexibles, P-trap, fitting the new sink + tap, pressure test, leak warranty
- Compliance certificate if your state issues them
- Timeline for the day, straight swap is 2–3 hours; if they want a full day, ask what’s included
A good plumber inspects under-sink before quoting, so they can see the existing isolation, the drainage age, and any rot in the cabinet base. Quotes done sight-unseen leave you exposed to “discovered” extras on the day.
When to wait
Don’t replace the sink alone if you’re:
- Renovating the kitchen within 2 years (the new sink might not fit the future layout)
- Selling within 6 months (buyers are usually neutral on sinks; the benchtop matters more)
- Selecting the sink before the new benchtop, choose benchtop first, then sink to fit
Kitchen sink replacement is one of the more reliable mid-tier plumbing jobs in Australia: predictable cost range, predictable timeline, and a tangible upgrade. It is also licensed work. Budget $600–$1,500 all-in for a straight swap with a quality sink and have a plumber check it on quote day. If a contractor or handyman tells you they’ll do it without a licence, get someone else.
Frequently asked questions
Can I change my own kitchen sink in Australia?
No. Replacing a kitchen sink involves disconnecting and reconnecting the water supply (the taps and stop valves) and the drainage (the waste, P-trap, and connection to the stack). Both are plumbing work and require a licensed plumber in every Australian state.
How long does it take to replace a kitchen sink?
A straight swap with the existing taps and benchtop is typically 2–3 hours. If new taps, a new mixer, or any benchtop work is involved, allow half a day to a full day.
How much does it cost to replace just the sink, not the benchtop?
$350–$900 typically for the labour, depending on access, the existing plumbing, and whether the cutout in the benchtop needs adjusting. Add the cost of the new sink ($150–$2,000+) and any new taps ($80–$800).
Do I need a new benchtop if I'm changing the sink?
Only if the new sink has different external dimensions to the old one, or if it's a different mount type (top-mount vs undermount). Otherwise the cutout is reused. A licensed plumber will tell you upfront whether the cutout works for your chosen sink.