At a Glance
The plumbing component of a bathroom renovation in Australia typically costs $3,000–$8,000 per bathroom. This covers rough-in pipework, fixture installation, and drainage, but not tiling, waterproofing, or electrical, which are separate trades quoted independently. Costs climb when fixtures move from their original positions, especially on concrete slab floors.
What's Included
A typical bathroom plumbing renovation covers:
- Rough-in plumbing (first fix) : new hot and cold supply lines, waste pipes, and drainage connections to AS/NZS 3500 Plumbing and Drainage
- Fixture installation (second fix) : fitting the toilet, basin, shower, and bath after tiling is complete. Fixtures supplied by the homeowner or quoted separately.
- Isolation valves : individual shut-offs for each fixture, allowing future maintenance without turning off water to the whole house
- Compliance testing : pressure testing supply lines and checking drainage falls meet code
- Two-stage visits : rough-in before waterproofing and tiling, then fit-off after tiling is done. Plan for two separate plumber visits, typically weeks apart.
Not typically included: waterproofing membrane (separate trade, must comply with AS 3740), tiling, electrical work (exhaust fan, lighting, heated towel rail), cabinetry, or fixture supply unless quoted as a package.
What Affects the Cost
- Layout changes : keeping fixtures in their existing positions is significantly cheaper than re-routing waste and supply lines. Moving a toilet even 500mm on a concrete slab means cutting the slab.
- Number of fixtures : a full bathroom (toilet, basin, shower, bath) requires more pipe runs, connections, and labour than a compact ensuite (toilet, basin, shower)
- Floor construction : concrete slab requires cutting and core-drilling for any fixture relocation. Timber floors allow easier sub-floor access for pipe runs.
- Wall type : double-brick (common in Melbourne and Adelaide) is harder and slower to chase pipes through than timber-framed plasterboard
- Pipe material : replacing old galvanised steel or lead pipes with modern PEX or copper adds cost but is often required in pre-1970 homes
- Access panels : concealed pipework behind tiles needs access points for isolation valves and traps, as required by current regulations
A fixture-in-place renovation in a timber-framed home with sub-floor access sits toward $3,000. A full layout change on a concrete slab in a double-brick home, with cast iron pipe replacement and slab cutting for new waste positions, pushes toward $8,000.
City and Regional Price Comparison
City-level differences: Sydney (NSW) sets the baseline for bathroom plumbing renovation costs. Melbourne tracks within 5% of Sydney pricing. Brisbane can be slightly cheaper due to the prevalence of high-set Queenslanders with accessible sub-floor plumbing that reduces labour time. Perth and Adelaide tend to run 10–15% higher, driven by smaller plumber pools and regional material costs.
Suburb and regional-level differences: Construction type varies significantly within each city and directly impacts plumbing complexity. Inner-city terraces in Paddington (Sydney) or Fitzroy (Melbourne) typically have cast iron waste pipes, narrow footprints, and limited access, pushing costs toward the upper end of the range. Older stone cottages in Norwood or Prospect (Adelaide) have thick masonry walls that are slow and expensive to chase pipes through. High-set Queenslanders in Woolloongabba or Paddington (Brisbane) have open sub-floor space that makes pipe runs straightforward. New-build estates in Oran Park (Sydney), Tarneit (Melbourne), or Springfield (Brisbane) have modern PEX plumbing and timber-framed walls on concrete slab, making fixture-in-place renovations the simplest jobs. The main cost variable in newer homes is whether the renovation involves moving fixtures on the slab.
How We Calculate
Estimates are based on current licensed Plumber rates adjusted for each state, standard material costs, and typical renovation complexity. All prices include GST. Ranges reflect the difference between a like-for-like fixture swap and a full layout change requiring slab cutting and new pipe runs. Waterproofing, tiling, and electrical costs are excluded.