Is your 200m² figure the right area?
| Measurement supplied | What to do | Common mistake |
|---|---|---|
| Actual sloping roof area | Use 200m² for covering and removal before any separate order allowance. | Applying pitch again. |
| Horizontal projection of the roof, including eaves | Convert each roof plane using its pitch. | Treating it as sloping surface area. |
| Total house floor area | Establish the footprint and roof geometry first. | Using both storeys as roof area. |
For a single-pitch 200m² roof projection at 25°, surface area is 200 ÷ cos(25°) = 220.7m². At a hypothetical $150–$200/m², that changes the covering-related total to about $33,100–$44,100. If the starting figure excludes eaves, add their projected area before the conversion.
Use the numbers you know
Roof-area converter
Calculated sloping area. Assumes the projected roof outline already includes eaves and has one pitch. No wastage added.
What do different quoted rates produce?
| Assumed quoted rate | 200m² total | 250m² total |
|---|---|---|
| $100/m² | $20,000 | $25,000 |
| $150/m² | $30,000 | $37,500 |
| $200/m² | $40,000 | $50,000 |
| $250/m² | $50,000 | $62,500 |
Use the numbers you know
Calculate using your own rates
Enter your own prices and dimensions to calculate. This tool does not supply a market rate or add GST.
How do published NZ prices help?
| 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 |
| Roof replacement, metal tiles, average NZ residential | $17,000–$45,000/job | complete project · GST not stated | New Zealand (national). 2026 guide; indicative prices for replacement on an average NZ residential property.Edwards & Hardy - New Roof Cost NZ: A 2026 Price Guide Published: 2026-03-16 · Checked 2026-09-28 |
| Standing seam (concealed fix) roof, installed per m² | $200–$280/m² | complete project · incl GST | Historical guideAuckland. Area basis not specified. Historical 2025 budgeting guide. Source includes GST, scaffolding and old-roof removal/disposal. It names older product ranges. Area basis is not fully defined; this is not a measured project invoice.Delta Roofing - Roof Replacement Cost NZ 2025 Complete Price Guide Published: 2025 · Checked 2026-09-28 |
The whole-job observations do not state that every roof is exactly 200m². Do not divide their endpoints by 200 and call the result a measured square-metre rate. The historical per-m² example can be scaled only on an explicitly assumed compatible area basis.
A good comparison keeps three layers apart: what the source actually published, any RoofHub arithmetic derived from it, and the supplier’s current written offer. A review date confirms that a page was checked; it does not make a 2025 rate a 2026 quote.
What belongs in the total?
- New covering, matching flashings and fasteners.
- Underlay and any required substrate or batten work.
- Removal, transport and disposal for a reroof.
- Site safety/access and the included hire period.
- Gutters, downpipes, insulation or repairs only where expressly included.
- GST shown on the complete total, with exclusions listed.
Compare inclusions line by line before comparing the final number. A quote with scaffold already included should not receive the estimator’s scaffold allowance again. Likewise, do not add roof removal to a published complete-reroof rate that already includes it.
Why can two 200m² roofs cost different amounts?
Area measures quantity, not all the work. Two roofs can share an area while one has much longer ridges, several valleys, restricted delivery access and more flashings. Record those quantities instead of assuming every difference can be explained by a flat percentage.
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
One scaffold serving several trades
Whitby, Wellington · Scaffolding
Erect It describes access for roofing, recladding and window work on the same property.
What it illustrates: Hire duration should follow all trades using the scaffold, not just the roofing crew.
- Roof price
- Not published
- Measured area
- Not published
For a roof with unresolved substrate condition, ask for a written process for opening-up discoveries: what is included, what is a provisional allowance, and what requires approval as a variation.
What information makes the estimate useful?
Bring a plan or measured roof area, material preference, existing roof type, storeys, pitch and access notes. The detailed estimator accepts component lengths as well as area. A contractor still needs to verify measurements and site conditions before issuing a quote.
Related questions
Is the example a quote for my home?
No. It demonstrates area multiplied by a stated rate. Site conditions, scope, product and current prices must still be confirmed.
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.
- marketColdrick Roofing: Re-roof in Tauranga - Page checked 2026-09-28. Publication date not stated. · contractor
- marketErect It Scaffolding: Whitby reroof, recladding and window installation (2026-08-24) - Page checked 2026-09-28. Publication date shown above. · contractor
- marketEdwards & Hardy - New Roof Cost NZ: A 2026 Price Guide (2026-03-16) - GST treatment not stated by source · roofer
- marketDelta Roofing - Roof Replacement Cost NZ 2025 Complete Price Guide (2025) - GST included · 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.
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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.