Having a roof over your head is essential, but understanding roof replacement costs doesn’t have to be complicated. Use our roofing calculator above for a quick estimate, or continue reading to learn what influences roof replacement costs and get a clearer picture of what you’ll pay for your new roof.

Step 1: Understand the Factors That Impact Roof Replacement Cost

Roof replacement costs are influenced by several key variables:

• Roof size: Roofing quotes are typically calculated per square metre. Larger roofs require more materials and labour, resulting in higher overall costs.
• Roof design: Different roof types—flat roofs, pitched roofs, or skillion roofs—come with varying installation requirements and material costs. The more complex your roof design, the higher the installation expense.
• Roof pitch: The slope of your roof affects both labour requirements and material needs. Steeper pitches demand additional safety measures and present greater installation challenges, increasing the cost per square metre.
• Roofing material: Your material choice significantly impacts total cost. Options range from Colorbond steel and concrete tiles to terracotta, slate, and metal roofing, each with different price points per square metre. Consider not just upfront cost, but also durability, aesthetics, and expected lifespan.
• Labour costs: Professional roofing contractors charge varying rates based on their expertise and experience. While highly skilled contractors command premium rates, their efficiency and quality workmanship often justify the investment.
• Site access: Difficult site access or multi-storey homes require additional equipment like scaffolding, which adds to your project cost.

Step 2: Calculate the Total Square Metres for Your Roof

To determine your roof size:

1. Measure length and width: Use a measuring tape to measure each roof section. For complex roof shapes, divide them into smaller, manageable sections and measure each individually.
2. Multiply length by width: Calculate the area of each section by multiplying its length and width measurements. Repeat for all sections.
3. Add all areas together: Sum the areas of all sections to determine your total roof area in square metres.

Safety Warning:

Only trained roofing professionals with proper safety equipment should work at height. Safer alternatives include using your home’s floor plan to estimate roof size, measuring from inside your home, or—the best option—contacting a professional roofing service that offers complimentary measurements during the quoting process.

Did you know? Quality roofing protects your home from weather damage while significantly improving energy efficiency and property value.

Step 3: Estimate the Cost of Materials

Once you know your roof area, multiply the total square metres by the cost per square metre of your chosen roofing material to estimate material costs.

Average Roofing Material Costs Per Square Metre (Australia)

Roofing material prices vary widely, from economical Colorbond options to premium slate tiles. The following costs are indicative averages:

• Colorbond steel: $18–$37 per m² (most affordable option)
• Concrete tiles: $45–$65 per m²
• Steel roofing: $50–$70 per m²
• Corrugated metal: $50–$70 per m²
• Asphalt shingles: ~$65 per m²
• Terracotta tiles: $80–$110 per m²
• Clay tiles: ~$100 per m²
• Timber roofing: ~$160 per m²
• Solar roofing tiles: ~$320 per m²
• Slate tiles: $200–$500 per m² (premium option)

How to Calculate Material Costs

While consulting an experienced roofing contractor provides the most accurate estimate, you can calculate a rough figure using this method:

1. Determine roof area: Use the square metre calculation from Step 2
2. Research material pricing: Find the average cost per square metre for your preferred roofing material
3. Multiply area by cost: Multiply your roof area by the material cost per square metre to estimate total material expenses

Alternatively, use our calculator above for an instant estimate.

Remember: Professional roofing installation requires experienced tradespeople working safely at height with appropriate safety equipment and insurance.

Step 4: Include Additional Expenses

Material costs are just one component of your total roof replacement budget. Also factor in:

• Labour costs: Professional installation typically ranges from $40 to $120 per hour. Project duration depends on variables including roof size, pitch, complexity, and site access.
• Old roof removal: Replacing an existing roof requires removal and disposal of old materials. Asbestos roof removal incurs significantly higher costs due to specialized handling, safety requirements, and disposal regulations.
• Additional components or customization: Custom features, complex architectural details, or specialty installations will increase your overall roof replacement cost.

Step 5: Get Multiple Quotes

To ensure competitive pricing and quality workmanship, obtain quotes from at least three reputable roofing contractors. Compare quotes carefully, evaluating:

• Quality and specifications of proposed materials
• Labour costs and project timeline
• Warranty coverage and duration
• Contractor credentials, insurance, and reputation
• Customer reviews and references

This comprehensive comparison helps you make an informed decision that balances cost with quality and reliability.