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Capital Gains Tax · Koste Knowledge Base

What Renovation Costs Can I Add to My Cost Base?

Published 26 June 2026 · Last updated 26 June 2026

Quick Answer

In Australia, renovation costs that improve or extend the property's value can be added to your cost base for CGT purposes. This includes structural improvements, such as extensions or major renovations. Costs must be capital in nature, not deductible repairs. Consult Division 43 of ITAA 1997 and speak to your accountant for specifics.

Renovating a property can significantly impact your capital gains tax (CGT) obligations. Understanding which renovation costs can be added to your property's cost base is crucial for calculating CGT accurately. The key is distinguishing between capital improvements and deductible repairs.

What Renovation Costs Can Be Added to Your Cost Base?

Under Australian tax law, specifically Division 43 of the Income Tax Assessment Act 1997, renovation costs that enhance or extend the property's value can be added to your cost base. These are typically capital improvements rather than repairs. Capital improvements include structural changes, such as adding a new room, updating a kitchen or bathroom, or significant landscaping projects. These costs can increase the cost base, reducing the capital gain and, consequently, the CGT payable when you sell the property.

A common misconception is that all renovation expenses can be added to the cost base. However, only those that are capital in nature qualify. Repairs or maintenance, which merely restore the property to its original condition, are generally immediately deductible and do not form part of the cost base.

How This Works in Practice

Consider a scenario where you own a 2008-built 3-bedroom house in Richmond, Melbourne, purchased for $750,000. You undertake a major renovation, adding a new bedroom and updating the kitchen, costing $150,000. These are capital improvements and can be added to your cost base, increasing it to $900,000. When you sell the property for $1,200,000, your capital gain is reduced to $300,000. Assuming a 37% marginal tax rate and eligibility for the 50% CGT discount, your tax liability is significantly reduced.

Professional Insight

In our experience, investors often overlook the importance of maintaining detailed records of renovation costs. One thing we frequently see is clients confusing repairs with improvements, leading to incorrect cost base calculations. What most investors don't realise is that even the cost of demolition and site preparation can be included if directly related to a capital improvement. Additionally, obtaining a Quantity Surveyor's report can help accurately apportion costs between capital improvements and repairs.

When Does the Answer Change?

  • Pre-1985 Properties: Properties acquired before 20 September 1985 are exempt from CGT, so renovation costs are irrelevant for CGT calculations.
  • Partial Year Ownership: If you own the property for part of the year, consult your accountant about how renovation costs can be apportioned.
  • Property Held in SMSF: Different rules may apply if the property is held in a self-managed super fund (SMSF).
  • Commercial Properties: Different depreciation and CGT rules can apply to commercial properties compared to residential ones.
  • When Should You Seek Professional Advice?

    While you can determine the cost base additions yourself, the specifics depend on individual circumstances. Consulting a Chartered Quantity Surveyor for depreciation and cost base reports, alongside your accountant, ensures accuracy. They can clarify which costs qualify as capital improvements and how these impact your CGT.

    What to Do Next

  • Compile Detailed Records: Gather all receipts and documentation related to renovations.
  • Consult a Quantity Surveyor: Obtain a professional report to distinguish capital improvements from repairs.
  • Review ATO Guidelines: Familiarise yourself with Division 43 of ITAA 1997.
  • Speak to Your Accountant: Discuss how these additions affect your CGT obligations.
  • Plan Future Renovations: Consider the tax implications of any further improvements.
  • Prepare for Sale: Ensure all cost base additions are documented before selling.
  • Frequently Asked Questions

    Can I add landscaping costs to my cost base?

    Yes, if the landscaping is a capital improvement that enhances the property's value, it can be added to your cost base.

    How are renovation costs reflected in my tax return?

    Renovation costs added to the cost base are not deductible annually but reduce your capital gain when you sell the property.

    Are there different rules for properties in New South Wales?

    The basic rules for adding renovation costs to the cost base are consistent across Australia, including New South Wales.

    Do I need a Quantity Surveyor's report for renovations?

    While not mandatory, a Quantity Surveyor's report can accurately distinguish between capital improvements and repairs.

    What if I renovate a property held in a trust?

    The renovation costs can still be added to the cost base, but consult your accountant for specific trust-related tax implications.

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    Written by Koste Team · Koste Chartered Quantity Surveyors · AIQS Member · RICS Member · TPB Registered · 1300 669 400 · info@koste.ai