Estimate Your Roof Replacement Cost in Australia
This roof replacement cost calculator is an indicative planning tool. It adjusts supply and install pricing for roof area, material, pitch, access, removal, insulation, skylights and gutters. Site conditions and scope still need to be confirmed during an inspection, so book a site visit for a firm quote.
Estimated Roof Replacement Cost
View detailed breakdown
What drives roof replacement costs in Australia?
Peninsula roofing costs depend on five key factors:
- Total roof area: Measured including pitch and overhangs—typically 1.1–1.4× your floor area
- Material and profile: Colorbond steel vs concrete/terracotta tiles, with profile affecting labour time
- Pitch and complexity: Steep roofs and multi-valley designs require more safety equipment and skilled labour
- Access and storeys: Difficult sites with narrow access or double-storey heights increase setup costs
- Scope additions: Insulation, sarking, skylights, and new gutters significantly impact total cost
Colorbond vs tiles: Peninsula pricing realities
Material choice affects both supply and installation costs on the Peninsula:
Colorbond steel advantages
- Faster installation: Lighter sheets mean quicker progress, reducing labour costs
- Lower structural load: Existing frames rarely need strengthening
- Coastal performance: COLORBOND Ultra resists salt air corrosion better than standard steel
- Easier removal: Less disposal weight and time compared to tiles
Tile considerations
- Higher material cost: Concrete and terracotta tiles carry premium pricing
- Slower installation: Individual tile placement takes more time than sheet roofing
- Weight factors: May require structural assessment or beam upgrades
- Coastal durability: Salt spray can cause tile surface degradation over time
Peninsula conditions affecting your roof choice
Local weather patterns influence both performance and maintenance costs:
Coastal exposure
Properties within 1km of Port Phillip Bay face increased salt air exposure. COLORBOND Ultra performs better than standard steel in these conditions, while tiles may show surface erosion over 15–20 years.
Wind and weather
Peninsula southerlies and storm activity favour well-fastened metal roofing. Our installations exceed minimum fixing requirements for improved wind resistance.
Thermal performance
Both Colorbond and tiles benefit from proper sarking and insulation. The calculator includes sarking and bulk insulation options that significantly improve comfort and energy efficiency.
When restoration beats replacement
Not every roof needs full replacement. Consider roof restoration if:
- Structure and sarking are sound (under 25 years old)
- Only surface coating or minor repairs are needed
- Budget constraints make staged works preferable
- Council approval timeframes favour restoration scope
Our Peninsula specialists can assess whether restoration or replacement offers better value for your specific situation. If replacement is recommended, our roof installation timeline guide explains the usual stages and causes of delay.
Using the calculator for a Colorbond or tile roof
The calculator prices three roofing materials: Colorbond or metal sheeting, concrete tile and terracotta tile. To compare a Colorbond roof with a tile roof for the same home, keep the roof area, pitch, roof type, storeys and site access the same and change only the material. The difference between the two results is the planning gap between the materials for that house, before anyone has inspected it.
Replacing a tiled roof with Colorbond is a common job on the Peninsula. For that estimate, choose Colorbond / Metal as the new material, tick removal and disposal, and set Existing roof to the tile on the house. Taking off tiles is heavier and slower than removing metal sheets, so the removal line uses $18 per m² for concrete tile or $22 for terracotta instead of $12 for metal, before GST. The inspection confirms the real cost. Add sarking or batts if you plan to install them at the same time, while the roof is off. Framing repairs found once the old roof is removed are outside the estimate and are confirmed on site. For Peninsula homes choose Melbourne / VIC as the region.
If you do not know the sloped roof area, the roof pitch calculator helps you work out the pitch to apply to your floor area. When you are ready to turn the estimate into a fixed price, see tile-to-Colorbond roof replacement on the Mornington Peninsula or Colorbond roofing in Mornington.
Can I compare Colorbond and tile in the calculator?
Yes. Run it twice with every setting the same except the material, then compare the two totals and their breakdowns.
Does the estimate cover a tile-to-Colorbond conversion?
It covers supply and installation of the new roof with standard flashings and fixings, plus an allowance for removing the old roof if you select it (set Existing roof to the tile type so the allowance reflects tile removal). Structural carpentry, framing repairs and asbestos are excluded and are assessed at inspection.
What roof area should I enter?
The sloped surface area of the roof. If you only know the floor area, multiply it by 1.1 to 1.4 depending on the pitch and the overhangs.
Roof replacement cost – FAQs
How much does a roof replacement cost in Australia?
In this calculator, a 150 m² single-storey gable roof in Victoria comes to about $23,000 to $32,000 for Colorbond and $26,000 to $36,000 for concrete tile, including removal of the old roof and GST. The lower figure is a low-pitch roof with easy access; the upper figure is a 15–30° pitch with standard access. Terracotta tile costs more. Other states use slightly different rates, and hip or complex roofs, a second storey, insulation, skylights and new gutters add to the total. Structural repairs and asbestos are excluded. These are planning figures, not a quote.
What's included in the calculator?
Supply & install of the chosen roofing, standard flashings, fixings, and any options you select such as sarking or gutters. Structural works and asbestos are excluded.
How accurate is the estimate?
It's a planning-level guide (±10–20%). We'll confirm after site inspection.
Colorbond or tiles — which costs more?
Material rates differ by region and profile. Colorbond is often lighter and faster to install; tiles can carry higher material cost and removal.
Do you service my suburb?
We cover the Mornington Peninsula & bayside — see locations.
Get a firm quote
Ready for precise pricing? Book a roof inspection or call 0485 095 175. We service the Mornington Peninsula & bayside suburbs.
Comparing materials? See asphalt shingle prices or request a fixed re-roofing quote.
Need a hand? See roof replacement on the Mornington Peninsula or request a quote.
Turn a roof cost estimate into a quote brief
Updated
A roof calculator helps organise planning, but its result is not a site quote. Use the estimate to identify assumptions you need checked: roof area, material, access, removal and any related components. If the input is uncertain, keep that uncertainty visible rather than treating the calculated total as a fixed budget.
When requesting a quote, say how the area was estimated and whether the roof has multiple sections, complex junctions or limited access. Include solar equipment and other items that may need coordination. Do not walk on the roof to obtain measurements; ask what information can be confirmed through an inspection or existing plans.
Ask the contractor to identify which calculator assumptions differ from the assessed property. Compare complete installed scopes, including disposal and nominated allowances, rather than one rate in isolation. Concealed damage and conditions outside the calculator can change the job. Keep the agreed material, exclusions and variation process in writing before relying on the estimate to authorise work.