Does changing the material always need building consent?
MBIE’s exemption guidance includes an example of replacing old clay tiles with profiled metal in the same position, while noting the need to consider increased wind uplift. It is an example under defined conditions, not automatic approval for every concrete-tile conversion. Confirm your scope with the designer and council where necessary. Sources: MBIE Building Performance.
What changes in the quote?
| Work item | What to establish before comparing prices |
|---|---|
| Removal and disposal | Existing material, access, disposal destination and whether the quoted rate covers the whole operation. |
| Support and fixings | Whether existing support can be retained, or purlins/battens, connections or strengthening need work. Sources: MBIE Building Performance. |
| Underlay and flashings | The proposed build-up and junction details, including penetrations. |
| Roof edges and rainwater | How the new covering meets eaves, barges, gutters and existing features. |
| Hidden work | An opening-up allowance and agreed variation process for discoveries. |
| Safety and protection | Access system, property protection, weather plan and hire duration. Sources: WorkSafe scaffold guidance. |
A lower cladding weight does not remove the need for the roof assembly to resist wind. Ask the contractor or designer to explain the complete system rather than accepting “it is lighter” as a structural assessment. Sources: MBIE Building Performance.
Which metal system should you compare?
Request options that are compatible with the measured pitch and roof layout. The appearance of long-run corrugate, a trapezoidal sheet and a pressed metal tile is different, but so are their component schedules. A tray option may require a different support build-up again.
Gerard Bond, for example, is a panel-based product with a stated 12° minimum. Metalcraft MC760 is a long-run profile with a published 3° starting minimum. Those figures are not enough to select a product without the manufacturer’s complete design requirements. Sources: Gerard Bond; Metalcraft MC760.
How should you estimate the conversion cost?
Use: new roofing system + old-covering removal/disposal + access + separately defined repairs and extras. When comparing an all-in reroof quote, first identify which of these it already contains. Do not layer the same allowances on again.
RoofHub’s detailed estimator uses a separate removal line. Its working rates are planning inputs, not a supplier promise or a hazardous-materials quote. For a tile-to-metal conversion, unresolved support work can be more important than a small difference in sheet price.
| What | Published price (NZD) | Basis | Notes |
|---|---|---|---|
| Roof replacement, longrun steel, average NZ residential (new roof/re-roof) | $15,000–$35,000/job | complete project · GST not stated | New Zealand (national). Materials ~40% / labour ~60% of a re-roof. Standard NZ residential roof typically 120-250 m2. GST basis not stated on page.Edwards & Hardy - New Roof Cost NZ: A 2026 Price Guide Published: 2026-03-16 · Checked 2026-09-28 |
What can published reroofs teach us?
Publisher-reported project
Replacement with associated upgrades
Tauranga · Custom Orb
Coldrick describes roughly a week of roofing work, with sarking, insulation and rainwater upgrades.
What it illustrates: Two reroof totals are not comparable until the associated work is matched.
- Roof price
- Not published
- Measured area
- Not published
Publisher-reported project
Damage uncovered under the old roof
Tamahere, Waikato · Gerard CF Shake
Gerard describes replacing asphalt roofing and dealing with damaged plywood and framing beneath it.
What it illustrates: Hidden substrate work belongs in a contingency and variation process, not an assumed fixed removal rate.
- Roof price
- Not published
- Measured area
- Not published
These are examples of associated upgrades and concealed work, not documented concrete-tile-to-metal price samples. We do not relabel them to make the evidence appear more complete.
What if you are not sure which tile you have?
Concrete tiles, older textured metal tiles and asbestos-cement products should not be treated as the same material. A visual guess should not select a non-asbestos removal rate. Obtain appropriate identification before work that might disturb suspect material. Sources: WorkSafe asbestos guidance.
- Keep any old installation or product paperwork.
- Describe what is known and what is uncertain to the contractor.
- Do not break, drill, scrape or pressure-wash suspect roofing to identify it.
- Request a scope-specific assessment before agreeing to a removal price.
Sources and review notes
Prepared by RoofHub editorial team. Reviewed . A source check confirms what a page states, not an independent inspection or invoice audit. Published project accounts are attributed to their publishers.
- primaryMBIE Building Performance: Exemption 1.1: general repair, maintenance and replacement - Examples explain the exemption; they do not determine consent requirements for an individual property. Page checked 2026-09-28. Publication date not stated. · government
- primaryWorkSafe New Zealand: Scaffolding in New Zealand - Page checked 2026-09-28. Publication date not stated. · government
- primaryGerard: Bond steel roofing tile - Page checked 2026-09-28. Publication date not stated. · manufacturer
- primaryMetalcraft: MC760 product specifications - Page checked 2026-09-28. Publication date not stated. · manufacturer
- marketColdrick Roofing: Re-roof in Tauranga - Page checked 2026-09-28. Publication date not stated. · contractor
- primaryGerard: Tamahere transformation with CF Shake (2022-03-03) - Page checked 2026-09-28. Publication date shown above. · manufacturer
- primaryWorkSafe New Zealand: Working with or near asbestos - Page checked 2026-09-28. Publication date not stated. · government
- marketEdwards & Hardy - New Roof Cost NZ: A 2026 Price Guide (2026-03-16) - GST treatment not stated by source · roofer
Original calculations are labelled as examples. Historical prices stay dated, missing fields stay unknown, and conflicting specifications are flagged. Sources are not endorsements or paid rankings. Read our methodology or report a correction.
Keep exploring
Apply this to your roof
Have measurements or a project question?
Use your dimensions in the detailed estimator, or send your question to the RoofHub team. A roofing contractor still needs to confirm the site, specification and final price.