Underpaying for plumbing causes hidden leaks, rotting floors, and premature bathroom renovations. Proper scoping and fair pricing ensure long-term durability. Below are plumbing-only costs (excluding demolishing, tiles, cabinetry, waterproofing, electrical) for accurate comparison.
What Plumbing Work Includes
- Replacing of existing fixtures and pipework.
- Drainage relocation (toilet, vanity, shower, bath, floor waste).
- Water supply rerouting (hot and cold tail-outs at correct heights).
- Installation of isolation valves.
- Fit-off of new tapware, showerheads, toilets, baths, and vanities.
- Gas connection (if relocating the gas hot water heater).
- Pressure testing and compliance certification.
Upgrades
1. Replacing old copper pipes with PEX involves important trade-offs.
Advantages of PEX:
- Low cost: The plastic material itself is significantly cheaper than copper.
- Easy installation: PEX is highly flexible, making it very easy to route and install with minimal joints.
Disadvantages of PEX:
- Vulnerability: Because it is plastic, PEX is inherently prone to developing cracks and suffering from sudden bursts.
- Unpredictable failures: Even completely new PEX pipes can unexpectedly rupture, risking severe water damage.
Why Copper Wins Long-Term:
While copper piping is definitely more expensive to purchase and install, this material has established a proven track record over many decades.
$1000 – $3000
2. Concrete floor works
Moving the toilet by a short distance of 300 mm may require cutting through concrete, laying a pipe and filling the gap with cement.
$500 to $1500
3. Replacement of cast-iron stack
These are common in older houses. If you were to replace them entirely with PWC, the cost could be as high as
$3,000
4. New water heater
Insufficient capacity of the hot water system. A new shower head might overload an old water heater with a capacity of up to 150 litres. It will need to be replaced with a more powerful water heater.
$1500 – $4000
5. In-wall toilet cistern
A modern toilet system in which the water cistern is located in a built-in space within the wall. Only the toilet bowl and the flush panel are visible from the outside, which creates a more spacious feel.
$1000
| Scope of Work | Price (AUD) | Notes |
|---|---|---|
| PEX vs Copper Pipes | $1,000 – $3,000 | Cheaper does not necessarily mean better |
| En-suite (same layout) | $3,000 – $5,500 | Direct replacement/installation |
| Standard bathroom (new layout) | $5,000 – $10,000 | Moving toilet, shower, bath tube, vanity |
| Bathroom + laundry combo | $8,500 – $14,500 | Includes new floor waste |
| New water heater | +$1,500 – $4,000 | Added to any base scope |
| Cast-iron stack removal | +$1,000 – $3,000 | Relevant for older homes |
| In-wall toilet cistern | +$500 – $1,000 | Per toilet |
| Extra | 10% | And that is in case something goes wrong |
