Estimate your roof area from the house footprint plus eaves, multiply by a pitch factor, then decide whether the roof is simple, average or complex. Use that to place your roof in the low, middle or high part of the 2026 bands on our cost guide, and add separate allowances for asbestos, gutters, solar refit and access. The result is a planning range, not a quote.
Why a worked method instead of a calculator
The live version of this page promised an interactive calculator. We have replaced it with a worked method because a calculator can only multiply an area by a rate, and the rate is the part that changes most between Gold Coast roofs. A steel re-roof on a simple low-set house in Nerang and one on a two-storey hip roof facing the surf at Mermaid Beach can differ widely per square metre. Working through the steps below gets you to a sensible range and, more importantly, helps you understand the quotes you receive.
There are no dollar figures on this page. Once you have worked through the steps, take your result to the 2026 price bands on our cost guide.
Step 1: Measure the footprint
Start with the area the roof covers on plan.
- Find the external dimensions of the house. Plans are best. Failing that, measure the walls from outside with a tape, or use an aerial image tool.
- Add the eaves. Gold Coast homes typically have eave overhangs; add the overhang to each side. For example, a house measuring 15 m by 10 m with 600 mm eaves becomes 16.2 m by 11.2 m.
- Multiply length by width for each rectangle and add any wings, garages or verandahs under the main roof.
Worked example: a low-set brick-and-tile home in Robina measures 16.2 m by 11.2 m including eaves (181 m²), plus a garage of 6.6 m by 6.6 m including eaves (about 44 m²). Footprint: about 225 m².
Step 2: Allow for pitch
A sloping roof has more surface than its footprint. Multiply the footprint by a pitch factor:
| Roof pitch | Typical on | Multiply footprint by about |
|---|---|---|
| 5° or less | Skillions, patios, newer steel roofs | 1.00 |
| 15° | Many steel roofs | 1.04 |
| 22.5° | Common tile pitch | 1.08 |
| 30° | Steeper tile roofs | 1.15 |
| 40° | Steep or character roofs | 1.31 |
Worked example: the Robina house has a 22.5° tiled roof. 225 m² × 1.08 ≈ 243 m² of roof surface.
If you do not know the pitch, compare the roof with the examples above, or ask the contractor; they will measure it.
Step 3: Rate the complexity
Look at the roof from the street and from an aerial image and count the features that add cutting and flashing time.
- Simple: one gable or a plain hip, no valleys, few penetrations.
- Average: a hip roof with one or two valleys, a few vents and perhaps a skylight.
- Complex: several hips and valleys, changes of level, dormers, two storeys, many penetrations, or tight access.
The Robina example has a hip roof with two valleys where the garage joins: average.
Step 4: Choose the job type
Decide which row of the price bands applies:
- old steel or iron to new steel;
- tile to Colorbond;
- tile to new tile;
- asbestos cement to new steel.
If you are unsure whether you need a full replacement, read the signs you need a roof replacement first.
Step 5: Adjust for Gold Coast conditions
Nudge your position within the band for local factors:
- Close to the surf: marine-grade steel and fixings push towards the top.
- Older house: batten replacement and tie-down upgrades are likely; move up.
- Two storeys or steep block: more scaffold and lifting; move up.
- Simple, accessible, single-storey, inland: towards the bottom.
Step 6: Add the extras separately
List the extras rather than burying them in the main figure. Typical ones are new gutters and downpipes (measure the gutter run around the house), solar panel removal and refit by a licensed electrician, skylight replacement, extra ventilation, asbestos gutters or eaves, and building approval if the change requires it.
Step 7: Put it together
For the Robina example: about 243 m² of roof, average complexity, tile to Colorbond, older house inland, single storey, with gutters and a solar refit as extras. That places the main job around the middle of the tile-to-Colorbond band, plus separate allowances for gutters and solar. That is a planning range to budget around while you get quotes.
Using your estimate
When the quotes arrive, check the roof area each contractor has used. If one is far from your estimate, ask why. Check that each quote includes the same items: battens, blanket, flashings, gutters, edge protection and disposal. A big price gap is usually a scope gap.
If your estimate is beyond your budget, talk to the contractor about staging (for example, the worst face first), choosing a different material, or repairs that buy time. Read financing options too.
Get the real figure
An inspection and written quote are free. Call 07 5241 1403 or use the form below.
General information about roofs on the Gold Coast, not advice about your roof. Rules, products and programs change; check with the body named (QBCC, City of Gold Coast, Workplace Health and Safety Queensland) before you act.