How to Quote Bathroom Renovation Jobs

Why bathroom quoting carries more risk per square metre than any other room

Bathrooms are small rooms with high stakes. The average Australian bathroom is 5 to 8 square metres, yet a full renovation runs $20,000 to $35,000 because every surface must be waterproofed, tiled, plumbed, and wired to code. That concentration of trades and compliance requirements into a small footprint is what makes bathroom work profitable for builders who scope thoroughly and dangerous for those who quote a round number from memory.

The biggest financial risk in bathroom work is waterproofing. A failed membrane discovered two years after handover means ripping out every tile, re-waterproofing, re-tiling, and replacing damaged fixtures at your cost. The biggest quoting risk is the floor type: a concrete slab home can add $1,000 to $3,000 to any plumbing relocation because drains require core drilling. Builders who identify both risks at the site visit and price them explicitly build profitable bathroom businesses. Those who absorb them into a competitive headline figure learn the lesson once.

This guide covers each component with real 2026 Australian benchmarks so you can build bathroom quotes that protect your margin on every job.

Step 1: Calculate your true cost per hour

Before pricing any bathroom job, work out what an hour of your time actually costs the business. This is your loaded hourly cost, covering everything required to have your crew on site with tools ready.

Your loaded hourly cost is the floor. Every hour on a bathroom job must recover this amount before any profit margin. A sole trader running lean sits around $65 to $75 per hour. A builder with an employee or two is closer to $90 to $110. Add your profit margin on top: at 35% gross margin, a $75 loaded cost becomes a $115 charge-out rate.

Use this number as your labour multiplier throughout the rest of this guide. When a task takes 4 hours, the labour line in your quote is 4 multiplied by your charge-out rate.

Step 2: Scope and price the demolition

Bathroom demolition means removing every surface and fixture down to the substrate: tiles off walls and floors, old waterproofing membrane stripped, vanity and toilet removed, shower screen out, and all waste carted to a skip bin or tip run. The substrate condition underneath determines what the renovation will actually cost, which is why demolition is the first trade on site and the most important scoping step.

Standard strip-out costs

Asbestos: the hidden cost that blows bathroom budgets

Any home built before 1990 in Australia may contain asbestos in bathroom wall sheeting, floor tiles, tile adhesives, and even the waterproofing membrane. Asbestos testing costs around $250 to $400 for a bathroom (2 to 3 samples sent to a NATA-accredited lab). The results take 1 to 3 business days.

If asbestos is found, licensed removal is legally required in every state and territory. Non-friable asbestos cement (the most common bathroom finding) costs $35 to $55 per square metre for removal, containment, and licensed disposal. A typical bathroom with 12 square metres of wall sheeting and 5 square metres of ceiling sheet runs about $3,000 to $5,000 for removal. Planned removal costs dramatically less than discovery mid-demolition: one case study showed $21,500 for planned removal versus $33,000 to $45,000 when asbestos was found unexpectedly after work had begun.

Always include an asbestos inspection allowance in your demolition pricing for pre-1990 homes. If asbestos is found, quote the removal as a separate line item with a provisional sum. This protects both your margin and the customer's expectations.

Step 3: Price waterproofing as a standalone certified line item

Waterproofing is the single most critical trade in a bathroom renovation. It is legally required under the National Construction Code (NCC) for all wet areas and must comply with Australian Standard AS 3740:2021. A failed membrane is the most expensive defect to rectify because fixing it means removing every tile, re-waterproofing, and re-tiling the entire area.

AS 3740:2021 compliance requirements

The standard sets specific requirements for membrane coverage, material classification, and installation detailing:

• Shower zone walls must be waterproofed to at least 1800mm above the finished floor level
• Surrounding walls must have the membrane extending at least 150mm up from the floor
• Floors must be fully waterproofed with the membrane graded to the drain waste puddle flange
• Bond breakers are required at all wall-to-wall, wall-to-floor, and hob-to-wall junctions where the membrane is bonded to the substrate
• Penetrations (pipes, drains) must be sealed with compatible collars or flanges to maintain membrane integrity
• Membrane materials must comply with AS/NZS 4858:2004, which classifies membranes by elastic properties and guides detailing requirements

Waterproofing costs

Always quote waterproofing as its own line item, separate from tiling. Include the inspection and certification cost. The customer sees that you are doing the work to code, and you have documentary proof of compliance if a dispute arises. Most waterproofing membranes require 24 to 72 hours of cure time before tiling can start, so factor this into your project schedule.

Wet rooms (bathrooms where the entire floor is the shower, with no hob or screen separating the shower area) require full waterproofing across all floor and wall surfaces, which increases coverage area and cost by 30 to 50 per cent over a standard shower-only waterproofing scope.

Step 4: Quote tiling by material, area, and complexity

Tiling is usually the largest single line item in a bathroom renovation by labour hours. A standard bathroom has 25 to 35 square metres of tileable surface when you add floor tiles plus wall tiles to full height or feature height. The cost varies dramatically with material choice, tile size, and pattern complexity.

Tile material costs (supply only)

Tiling labour costs

Putting it together

A standard 6 sqm bathroom tiled floor to ceiling with 600x300 porcelain tiles (30 sqm total area, straight lay) costs approximately $1,200 to $3,600 in tile supply plus $1,350 to $2,100 in labour, totalling $2,550 to $5,700. Upgrading to herringbone pattern adds 30 to 50 per cent to the labour line. Switching to natural marble doubles the material cost. Always break your tiling quote into floor and wall sections with the tile selection, area, and pattern named explicitly so the customer can see exactly what drives the price.

Additional costs to include: tile adhesive ($15 to $30 per 20kg bag, roughly one bag per 4 to 5 sqm), grout ($10 to $25 per bag), silicone sealant for wet-area junctions ($10 to $20 per tube), tile sealer for natural stone ($10 to $15 per sqm), and waterproofing primer if specified by the membrane manufacturer.

Step 5: Include plumbing as a separate trade package

Plumbing is the trade most affected by the existing bathroom layout. A like-for-like renovation where fixtures stay in the same position costs a fraction of a layout change because the drains and water supply lines are already in place. The floor construction (timber subfloor versus concrete slab) is the second variable, because relocating drains in a concrete slab requires core drilling.

Plumbing costs by scenario

Quoting plumbing as a trade package

Quote plumbing as two line items: rough-in (first fix, before waterproofing and tiling) and second-fix (after tiling, installing fixtures). This matches how the plumber bills you and makes the sequence clear to the customer. Specify the number of plumbing points and whether any fixtures are moving. If you are the head contractor managing subcontracted plumbers, add your margin to their trade price.

The biggest plumbing risk in a bathroom renovation is discovering non-compliant or corroded pipework behind the walls. Galvanised steel pipes (common in homes built before 1980) and polybutylene pipes (used in the 1980s and 1990s) often need replacing when they are exposed during a strip-out. Include a provisional sum or exclusion clause for concealed pipe replacement so you are covered if the scope expands.

Step 6: Include electrical as a separate trade package

Bathroom electrical work must comply with AS/NZS 3000 (the Australian Wiring Rules), which defines electrical zones for wet areas. All bathroom electrical work requires a licensed electrician, and the completed work must be tested and certified.

Electrical costs by component

Like plumbing, quote electrical as rough-in (first fix, before waterproofing) and second-fix (after tiling). The electrician runs cables and positions junction boxes during rough-in, then installs light fittings, fans, switches, and power points after the tiler finishes. Coordinate the rough-in timing so electrical cables are in place before the waterproofing membrane goes on.

Step 7: Price the vanity, fixtures, and shower screen

Fixtures are the most visible part of a bathroom renovation. They are also the line items where customer-supplied versus builder-supplied decisions create the most quoting confusion. Always clarify upfront who is supplying each fixture, and specify the exact product, model, and finish in your quote.

Vanity costs

Wall-hung vanities require solid wall blocking behind the tiles (installed during the rough-in carpentry stage), which adds $100 to $300 to the framing cost. Specify this in your quote so the customer understands why wall-hung costs more than freestanding beyond the unit price alone.

Other fixtures

Shower screens

If the customer is supplying fixtures, include an installation allowance per item in your quote ($100 to $300 each depending on complexity). State clearly that your warranty covers installation workmanship only, not the customer-supplied product. If you are supplying fixtures, quote each item as a separate line with the exact product name, model number, and finish so there is no ambiguity at installation time.

Step 8: Include painting, finishing, and clean-up

Painting in a bathroom covers the ceiling, any untiled wall areas (above tile height to ceiling), the door frame, and any exposed trim. Bathroom-grade paint with mould resistance is required for wet areas.

Complete bathroom renovation benchmarks (2026)

These benchmarks reflect all-in pricing for typical bathroom renovations across Australia in 2026. Use them to sanity-check your own quotes against market expectations.

The national average bathroom renovation cost in 2026 sits around $26,000 for a full renovation. Smaller bathrooms (ensuites, powder rooms) cost more per square metre because the fixed plumbing, waterproofing, and electrical costs are spread across fewer square metres. Sydney and Melbourne trend 10 to 20 per cent above the national average. Regional areas and smaller capitals tend to run 5 to 15 per cent below.

Licensing requirements by state and territory

Bathroom renovation work involves multiple licensed trades. The head contractor (builder) needs a licence in most states above certain thresholds, and the plumber, electrician, and waterproofer each need their own licences regardless of project value.

Plumbing, electrical, and waterproofing work always requires separately licensed tradespeople in every state and territory, regardless of the overall project value. Gas fitting (if relocating gas hot water or adding gas bayonets) requires a licensed gas fitter. Quote each licensed trade as a separate line item so compliance is visible.

How to structure and present the quote

An itemised bathroom quote converts better than a lump-sum figure because customers can see where their money goes. It also protects you: when the customer asks to upgrade from ceramic to marble, you adjust one line instead of renegotiating the whole job.

Recommended quote structure

1. Demolition and strip-out (asbestos testing noted if applicable)
2. Carpentry and framing (wall blocking for wall-hung fixtures, hob framing, niche framing)
3. Plumbing rough-in (first fix)
4. Electrical rough-in (first fix)
5. Waterproofing (membrane type, certification included)
6. Tiling (floor and walls as separate sub-lines, tile material and pattern specified)
7. Plumbing second-fix (toilet, basin, tapware, shower mixer install)
8. Electrical second-fix (lights, fan, towel rail, GPOs, switch plates)
9. Vanity (supply and install, product specified)
10. Shower screen (supply and install, type specified)
11. Painting (ceiling and walls above tile line)
12. Accessories (towel rails, robe hooks, toilet roll holder, mirror)
13. Clean-up (grout haze removal, final clean, waste disposal)
14. Provisional sums / exclusions (asbestos if pre-1990, concealed pipe replacement, structural remediation)

Trade scheduling order

The sequence of trades in a bathroom renovation is fixed by the waterproofing inspection requirement. You cannot tile until waterproofing is inspected and certified, and you cannot waterproof until plumbing and electrical rough-in is complete. The schedule runs:

1. Demolition and strip-out (1-2 days)
2. Asbestos removal if required (1-3 days, licensed contractor)
3. Carpentry and framing (1 day)
4. Plumbing rough-in (1 day)
5. Electrical rough-in (1 day, can overlap with plumbing)
6. Waterproofing (1 day application + 24-72 hours cure)
7. Waterproofing inspection (half day)
8. Tiling (3-5 days for a standard bathroom)
9. Grout and silicone (1 day + cure time)
10. Plumbing second-fix (1 day)
11. Electrical second-fix (half day)
12. Vanity and shower screen install (1 day)
13. Painting (1 day)
14. Accessories and final clean (half day)

A standard full bathroom renovation takes 2 to 4 weeks from demolition to handover when trades are scheduled tightly. Premium or complex renovations take 4 to 8 weeks. Communicate the schedule to the customer at quoting stage so they can plan for the bathroom being out of service.

Quote presentation

Send the quote within 48 hours of the site visit. Present it as a branded document or send it through Xero so it looks professional and is easy to accept. Follow up within 48 hours of sending. Include your licence number, insurance details, and any applicable warranty terms. For jobs above $20,000 in NSW (and similar thresholds in other states), a formal written contract is legally required.

Margin targets and contingency planning

Target a gross profit margin of 30 to 40 per cent on bathroom renovations. Bathrooms carry higher defect risk than most renovation work because waterproofing failures are expensive to rectify and can surface years after handover. Your margin needs to absorb the cost of returning to fix warranty items.

A 35% gross margin on a $30,000 bathroom yields $10,500 in gross profit. From this you cover your fixed overheads (vehicle, insurance, office, admin, accounting) before reaching net profit. If your actual margins consistently fall below 25 per cent, tighten your scoping or pricing process.

Contingency and exclusions

Always include a contingency line or exclusion clause for concealed conditions. The most common discoveries during bathroom strip-out are:

• Asbestos in wall sheeting, floor tiles, or adhesives (pre-1990 homes)
• Rotted timber framing behind the shower recess (from previous waterproofing failure)
• Non-compliant or corroded plumbing (galvanised steel, polybutylene)
• Inadequate floor structure for new fixtures (especially freestanding baths upstairs)
• Non-compliant electrical wiring requiring switchboard upgrade
• Termite damage in framing

A provisional sum of $1,500 to $3,000 for concealed conditions is reasonable for a standard bathroom renovation. Alternatively, list these items as exclusions with a note that they will be quoted separately if discovered. Either approach protects your margin and sets the customer's expectations before work begins.