Yes — for a standard bathroom retile, you absolutely can price the job yourself without hiring a quantity surveyor (QS). QS professionals are most valuable on large commercial or complex residential builds. For a bathroom retile, a methodical DIY approach, a few supplier quotes, and some basic maths will get you a solid estimate.
Why You Probably Don't Need a QS for a Retile
A quantity surveyor prepares detailed cost plans and bills of quantities for construction projects. Their expertise shines on new builds, major renovations, or insurance reinstatement work. A bathroom retile, while not trivial, is a well-defined scope — you're measuring a room, selecting materials, and getting labour quotes. That's well within reach for most homeowners.
That said, if your bathroom retile is part of a larger renovation involving structural changes, waterproofing compliance, or a building consent, a QS or experienced builder can help you avoid costly surprises.
Step 1 — Measure Your Bathroom Accurately
Start by measuring the floor area and wall areas you want to tile. Use a tape measure and record everything in metres.
- Floor: Length × Width = m²
- Walls: Measure each wall section separately (Height × Width), then subtract openings like windows, doors, and the vanity area
- Shower box: Measure each internal face separately
Add all your wall and floor areas together to get your total tile area in m².
Allow for Wastage
Always add a 10–15% wastage allowance on top of your measured area. Cuts around corners, outlets, and fixtures eat into tiles quickly. If you're using large-format tiles or a diagonal pattern, push that to 15–20%.
Step 2 — Calculate Your Tile Quantities
Once you have your total m² (including wastage), check the coverage per box on the tile packaging — most suppliers list this clearly. Divide your total area by the coverage per box to find how many boxes you need, then round up to the nearest whole box.
For example: 18 m² total area ÷ 1.44 m² per box = 12.5 boxes → buy 13 boxes.
You can check tile ranges and coverage information at Bunnings or Mitre 10, or visit a specialist tile supplier for a wider selection.
Step 3 — Estimate Materials Costs
Beyond tiles, a retile job involves several other materials. Here's a typical list:
| Item | Notes |
|---|---|
| Tiles | Price varies enormously by style and size |
| Tile adhesive | Check it suits your substrate (e.g. wet areas need flexible adhesive) |
| Grout | Match colour to your tiles; allow for joint width |
| Waterproofing membrane | Required in wet areas under NZ Building Code clause E3 |
| Tile trim / edge strips | For exposed edges and corners |
| Silicone sealant | For movement joints at corners and junctions |
| Tile spacers | Consistent joint width |
For wet areas like showers, waterproofing is not optional — it's required under the NZ Building Code to prevent moisture damage. Products from suppliers like Ardex, Mapei, or Sika are commonly used by NZ tilers. Always follow the manufacturer's application instructions.
Step 4 — Get Labour Quotes
Labour is typically the biggest variable in a retile budget. Tiler rates vary by region, complexity, and tile size. As a rough guide only, tiling labour in NZ can range from around $60–$120+ per hour, or tilers may quote a per-m² rate — but get at least two or three written quotes to compare.
Factors that affect labour cost include:
- Removing existing tiles (demo work adds time)
- Condition of the substrate underneath
- Tile size and pattern complexity
- Access and room size
- Whether waterproofing is included
You can find qualified local tilers on tradedirectory.co.nz to request quotes.
Step 5 — Don't Forget Hidden Costs
A few costs that homeowners often overlook:
- Tile removal and disposal — skip bin hire or tip fees
- Substrate repairs — if the existing wall lining (e.g. GIB Aqualine or fibre cement sheet) is damaged, it needs replacing before tiling
- Plumbing adjustments — repositioning tapware or waste fittings is restricted plumbing work and must be done by a licensed plumber registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB)
- Contingency — add 10–15% to your total estimate for unexpected issues
When to Call a Professional
While pricing the job yourself is straightforward, there are situations where you should bring in qualified tradespeople:
- Any plumbing work (moving pipes, waste fittings, tapware) must be done by a licensed plumber — this is legally restricted work under the Plumbers, Gasfitters and Drainlayers Act 2006
- If you're unsure whether your existing waterproofing is compliant or intact, have a tiler or builder assess it before retiling
- If the retile is part of a larger bathroom renovation that may require a building consent, check with your local council first — MBIE Building Performance has guidance on what triggers consent
- For insurance claims or disputes, a QS or licensed building practitioner (LBP) may be required to provide a formal assessment
Safety note: If you're doing any demo work yourself, be aware that tiles in older homes may be fixed with adhesives containing hazardous materials such as asbestos. If in doubt, check with WorkSafe NZ before starting.
Site Safe
Licensed Building Practitioner (LBP)
ISO 9001 / 45001 / 14001
NZ Institute of Building (NZIOB)
