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How Being an Owner-Builder Affects Your Depreciation

Published 26 June 2026 · Last updated 26 June 2026

Quick Answer

An owner-builder is someone who takes the role of a builder to construct or renovate their own property. This affects depreciation as the owner-builder must ensure that all costs are accurately documented for Division 40 and Division 43 claims. Professional advice is crucial to maximise potential deductions.

An owner-builder is someone who assumes the role of a builder to construct or renovate their own property, often to save on costs. While this can be a rewarding venture, it introduces complexities in claiming depreciation, which is crucial for maximising tax benefits.

Under Division 40 of ITAA 1997, you can claim depreciation on plant and equipment, while Division 43 covers capital works deductions for structural improvements. As an owner-builder, you're responsible for ensuring all costs are meticulously documented. This means tracking every receipt, invoice, and contract to substantiate your claims. The most common misconception is that owner-builders can claim depreciation as if they were commercial builders, but the ATO requires detailed costings and evidence of expenses.

Take a practical example of a 2010-built 4-bedroom house in Geelong, purchased for $900,000. As an owner-builder, you renovate the kitchen and bathrooms, spending $50,000 on plant and equipment and $100,000 on structural improvements. Under Division 40, you could claim depreciation on new appliances, cabinets, and fixtures. Assuming a 20% depreciation rate on the plant and equipment, you could deduct $10,000 in the first year. For Division 43, assuming a 2.5% rate over 40 years, you'd claim $2,500 annually on the structural improvements. At a 37% marginal tax rate, this reduces your tax bill by $4,625 in the first year.

In our experience reviewing thousands of properties across Australia, owner-builders often underestimate the importance of maintaining a detailed record of all construction costs. Many fail to realise that without proper documentation, the ATO may disallow their claims. Additionally, owner-builders frequently miss out on claiming eligible depreciation for assets they assumed were ineligible, such as plumbing and electrical systems. Another common oversight is not engaging a professional Quantity Surveyor early in the process, which can lead to missed opportunities for maximising deductions.

The answer can differ depending on your situation. If you acquired a second-hand property after 9 May 2017, the ability to claim Division 40 depreciation on used plant and equipment is restricted. Properties built before 1987 may not qualify for Division 43 deductions unless substantial renovations have been made. If the property is held within a Self-Managed Super Fund (SMSF), different rules apply, particularly concerning the fund's ability to claim deductions. Joint ownership can also complicate claims, as depreciation must be apportioned according to ownership percentage. A partial year of ownership requires prorating deductions based on the time held.

Given the complexities involved, consulting both a Chartered Quantity Surveyor and an accountant is essential. They can ensure all documentation is in order, maximise your deductions, and help navigate the nuances of ATO requirements effectively. Each property, and indeed each owner-builder situation, can have unique factors that influence the optimal depreciation strategy.

To make the most of your owner-builder status:

  • Keep meticulous records of all construction costs, including receipts and contracts.
  • Engage a professional Quantity Surveyor early in the process to ensure accurate cost assessments.
  • Consult with an accountant to understand how depreciation fits into your overall tax strategy.
  • Review ATO guidelines regularly to stay compliant with current legislation.
  • Consider professional advice if your property situation involves complexities like joint ownership or SMSF.
  • Reassess your depreciation schedule annually to ensure all eligible deductions are claimed.
  • Frequently Asked Questions

    Can owner-builders claim depreciation on their own labour?

    No, owner-builders cannot claim depreciation on their own labour. Only the cost of materials and contracted services are eligible for depreciation claims.

    How does being an owner-builder affect my tax return?

    As an owner-builder, you must ensure all construction costs are accurately documented and claimed in your tax return under Division 40 and Division 43. Failure to do so can affect your tax liabilities.

    Are there state-specific regulations for owner-builders?

    Yes, each Australian state has specific regulations for owner-builders, including permits and insurance requirements. It's essential to check with your local authority before starting construction.

    What happens if I sell my owner-built property?

    If you sell your property, any depreciation claimed may affect your capital gains tax calculations. Consult an accountant to understand the implications.

    Can I claim depreciation on assets acquired second-hand?

    For properties acquired after 9 May 2017, depreciation on second-hand assets is restricted under Division 40. Consult a Quantity Surveyor to explore your options.

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