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What is a Base Building vs Fit-Out for Depreciation?

Published 26 June 2026 · Last updated 26 June 2026

Quick Answer

In commercial property, a 'base building' refers to the core structure and essential systems like the roof, walls, and plumbing, covered under **Division 43** for depreciation. A 'fit-out' includes interior elements like partitions and finishes, often depreciated under **Division 40**. Understanding these differences is crucial for accurate tax deductions.

The distinction between a base building and a fit-out is pivotal in commercial property taxation. A base building typically includes the core structure — walls, roof, floors, and essential services such as plumbing and electrical systems. These components fall under Division 43 of the Income Tax Assessment Act 1997, allowing for capital works deductions over a set period.

Conversely, a fit-out covers the interior elements added to the building to make it functional for a specific business purpose. This includes partitions, lighting, carpets, and other finishes. These are considered plant and equipment and are depreciated under Division 40. The effective life of these assets varies, impacting the rate at which they can be depreciated.

Common misconceptions often arise around what elements qualify as base building versus fit-out. For instance, while air conditioning might seem part of the building, it is actually a fit-out item for depreciation purposes.

To see how this plays out, consider a typical scenario: A business owner in Melbourne invests in a commercial property, spending $1 million on the base building and $300,000 on a custom office fit-out. The base building, under Division 43, provides a deduction at a rate of 2.5% per annum, equating to $25,000 annually. The fit-out, under Division 40, might allow for accelerated depreciation depending on asset types, leading to potentially higher upfront deductions.

In our experience reviewing thousands of properties across Australia, a common pattern is the underestimation of fit-out value, leading to missed tax savings. Many investors overlook the need for a detailed depreciation schedule, which can significantly optimise tax outcomes. Another frequent oversight is failing to update the schedule after refurbishments, which can alter the depreciation landscape significantly.

The answer can differ depending on your situation. For example, properties acquired after 9 May 2017 face restrictions on claiming Division 40 for second-hand plant and equipment. Additionally, properties owned by a self-managed superannuation fund may have different implications due to specific tax rules. Joint ownership can also complicate depreciation claims, requiring careful apportionment.

Given these complexities, obtaining professional advice is crucial. A Chartered Quantity Surveyor can provide a detailed depreciation schedule, ensuring you maximise your claims. An accountant can integrate this into your overall tax strategy, ensuring compliance and optimal tax outcomes.

  • Identify whether your property elements are base building or fit-out.
  • Obtain a detailed depreciation schedule from a Chartered Quantity Surveyor.
  • Consult with your accountant to integrate depreciation into your tax strategy.
  • Regularly update your depreciation schedule post-renovations.
  • Review your depreciation claims annually to ensure compliance.
  • Consider any changes in ownership structure or property usage that might affect depreciation.
  • Frequently Asked Questions

    What qualifies as a base building?

    A base building includes the structural elements like the roof, walls, and essential services, depreciated under **Division 43**.

    How is a fit-out depreciated?

    Fit-out items, such as partitions and lighting, are considered plant and equipment and are depreciated under **Division 40**.

    Can fit-out costs be claimed immediately?

    Some fit-out costs may be eligible for immediate deduction if they qualify as low-value or low-cost assets, subject to specific criteria.

    Are there state-specific rules for depreciation?

    While depreciation rules are federal, some state incentives or grants can influence the overall cost base of a project.

    How do I report depreciation on my tax return?

    Depreciation is reported in your tax return as part of your overall deductions. Your accountant can assist in ensuring it is correctly filed.

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