Planning a bathroom renovation? The plumbing work is one of the most critical—and potentially costly—parts of the project. Here’s what you need to know before you start.

Before You Begin

1. Get a Plumbing Assessment

Before finalising your design, have a plumber assess your existing plumbing. They can tell you:

• Current pipe condition and material
• Water pressure adequacy
• Hot water system capacity
• Drainage requirements
• What’s possible within your budget

2. Understand Plumbing Costs

Plumbing typically accounts for 15-25% of a bathroom renovation budget. Costs increase significantly if you:

• Move fixtures from existing positions
• Add new fixtures (double vanity, bidet)
• Need to access pipes in walls or floors
• Have old pipes requiring replacement

3. Check Regulations

Victorian plumbing regulations require:

• Licensed plumber for all work
• Compliance certificates
• Council approval for some changes
• Proper drainage falls and venting

Plumbing Checklist by Area

Toilet

• Confirm floor waste position
• Check water supply location
• Consider wall-hung vs floor-mounted
• Ensure adequate clearance (min 450mm each side)
• Plan for concealed cistern if wall-hung

Shower

• Choose shower type (fixed, handheld, rain)
• Position mixer tap/taps
• Plan floor waste location
• Ensure waterproofing compliance
• Consider niche shelf drainage
• Check hot water flow rate for rain showers

Vanity/Basin

• Position water supply points
• Locate waste pipe
• Plan for single or double basin
• Consider mixer or separate taps
• Allow for storage around pipes

Bath (if applicable)

• Position waste (floor or wall)
• Locate water supply
• Plan for freestanding or built-in
• Consider overflow requirements

Moving Fixtures: What It Really Costs

Easy (Lower Cost)

• Replacing taps (same position)
• New toilet (same position)
• Like-for-like shower replacement

Moderate (Additional Cost)

• Moving basin along same wall
• Adding towel rail heating
• Upgrading to larger shower

Complex (Significant Cost)

• Moving toilet position
• Relocating shower
• Adding fixtures (second basin, bidet)
• Changing from bath to shower (or vice versa)

Common Renovation Mistakes

1. Not Budgeting for Hidden Issues

Old bathrooms often have:

• Corroded pipes needing replacement
• Inadequate waterproofing
• Non-compliant drainage

Always budget 10-15% contingency for unexpected plumbing work.

2. Choosing Form Over Function

That beautiful freestanding bath might not work if:

• Water pressure is inadequate
• Drainage position doesn’t align
• Hot water system can’t fill it efficiently

3. Forgetting Ventilation

Proper bathroom ventilation prevents:

• Mould growth
• Paint deterioration
• Mirror fogging

Extraction fans should vent outside, not into the roof space.

4. Ignoring Water Pressure

Low water pressure affects:

• Rain shower performance
• Filling time for baths
• Simultaneous fixture use

Test your pressure before choosing fixtures.

Timeline Considerations

Rough-In Stage

First fix plumbing happens after demolition:

• Water supply pipes installed
• Drainage positioned
• Hot water connected
• Typically takes 1-2 days

Fit-Off Stage

Second fix after walls and waterproofing:

• Fixtures installed
• Taps connected
• Final connections made
• Testing completed
• Typically takes 1 day

Allow Time For

• Waterproofing to cure (24-48 hours minimum)
• Tiling before fit-off
• Inspection sign-offs

Questions to Ask Your Plumber

1. Can my existing pipes support the new design?
2. Does my hot water system have enough capacity?
3. Will any pipes need replacing?
4. What’s included in the quote?
5. Who handles the compliance certificate?
6. What warranty do you provide?

Our Bathroom Renovation Services

Hankook Plumbing works on bathroom renovations throughout Melbourne’s eastern suburbs. We offer:

• Pre-renovation assessments
• Complete rough-in and fit-off
• Coordination with your builder or tiler
• Direct project management
• All compliance documentation
• Quality workmanship guarantee

Planning Your Renovation?

Get the plumbing right from the start. We can review your plans, give you accurate quotes, and ensure your renovation runs smoothly.

Call 0407 756 172 for a consultation.