Depreciation is one of the most powerful — and most underused — tax deductions available to Australian property investors, yet the rules governing it are split across two distinct legislative divisions of the Income Tax Assessment Act 1997. Division 40 covers plant and equipment assets such as carpet, appliances, and hot water systems, while Division 43 covers the structural shell of the building itself. Knowing how each division works, what qualifies, and where the post-2017 restrictions apply can meaningfully improve your after-tax cash flow on any investment property. For the full breakdown, see our Australian Property Tax Guide.
What Division 43 Covers — and Why It Matters for New Builds
Division 43 is the capital works deduction. It applies to the structural components of a building — the foundations, walls, roofing, fixed flooring, windows, and permanently affixed fitments that are considered part of the physical structure. The ATO allows investors to write off the construction cost of an eligible building at a flat rate of 2.5% per year over 40 years, provided the building was constructed after 15 September 1987. This rate reflects the assumption that the structural fabric of a building depreciates uniformly across four decades of use.
The 40-year effective life and the 2.5% annual write-off rate means the Division 43 deduction is predictable but modest on a year-by-year basis. However, compounded across a holding period of a decade or more, it can represent a substantial reduction in taxable income. For a newer investment property, the deductible capital works base is directly tied to the actual construction cost — which is why quantity surveyors are engaged to estimate the original build cost when that figure is not known. The ATO accepts quantity surveyor reports as sufficient evidence for these estimates.
For investors, the practical implication is clear: properties built after September 1987 are eligible, and newer construction maximises the Division 43 base because less of the 40-year write-off period has elapsed. A brand-new house or apartment purchased at completion carries the full 40 years of potential deductions ahead of it. An older eligible property purchased mid-life still carries the remaining years of deductions — the entitlement transfers to each successive owner during the 40-year window. Renovations and improvements made by any owner after 1987 also create a fresh Division 43 entitlement for those specific works.
Investors purchasing established properties should always obtain a quantity surveyor report before lodging their first tax return on the property. The cost of the report is itself tax-deductible, and the deductions it unlocks typically far exceed the fee. The ATO's depreciation rules do not allow investors to self-assess the construction cost — an independent estimate is required.
Division 40: Plant and Equipment After the 2017 Rule Change
Division 40 covers what the ATO calls plant and equipment — removable or mechanical assets within a property that have a finite effective life determined by the ATO's Tax and Superannuation Laws Amendment (2017 Measures No. 1) Act 2017. This legislation, which took effect from 9 May 2017 (Budget night), fundamentally changed who can claim Division 40 deductions on residential investment properties. Before that date, any investor could claim depreciation on plant and equipment regardless of whether they were the original purchaser. After that date, the rules split into two categories.
For properties where the investor installs new plant and equipment themselves — new carpet, a new dishwasher, new air-conditioning units — Division 40 deductions remain fully available. The investor claims depreciation over the ATO-prescribed effective life of each asset. Different assets carry different effective lives: a carpet may have an effective life of ten years, while a hot water system may have a shorter or longer schedule depending on type. Investors can choose between two depreciation methods for each asset — the prime cost method, which writes off the asset in equal annual amounts, or the diminishing value method, which front-loads deductions in the early years of ownership.
The critical restriction introduced in 2017 applies to second-hand plant and equipment in residential properties. If an investor purchases an established residential property and that property contains existing plant and equipment items — carpets, blinds, appliances installed by a previous owner — those items cannot be depreciated under Division 40. The assets are essentially quarantined from depreciation claims. This rule applies specifically to residential property held to produce rent. Commercial property investors and owner-occupiers are not affected in the same way.
For investors buying established residential rental properties, Division 40 deductions are now largely limited to assets they install themselves after settlement. The practical effect is that new builds and substantial renovations deliver materially greater depreciation benefits than older, unimproved stock — a structural tax incentive favouring new construction that the ATO has embedded into the depreciation framework since 2017.
The diminishing value method is generally favoured by investors with a shorter expected holding period because it accelerates deductions into the earlier years — maximising the time-value benefit of the tax saving. Investors planning a long hold often find the prime cost method produces a more stable annual deduction. Either way, the method must be applied consistently to each individual asset once chosen.
The Role of Quantity Surveyors and ATO Compliance
The ATO requires that depreciation claims on investment property be supported by a depreciation schedule prepared by a qualified quantity surveyor or similarly qualified professional. A depreciation schedule itemises both Division 43 (capital works) and Division 40 (plant and equipment) deductions for the property, year by year, over the effective life of each component. This document forms the evidentiary basis for the deductions claimed in each year's tax return. The ATO's data-matching capability means rental income and expense claims are routinely cross-checked against property records, loan data, and council information.
When purchasing a property, investors should request the existing depreciation schedule from the vendor where one exists. However, even an existing schedule may need to be reviewed or rewritten if the investor has undertaken renovations, if the property's use has changed, or if the previous schedule is outdated. Renovation expenditure creates a new Division 43 base for those specific works, and newly installed assets create fresh Division 40 entitlements — both of which should be captured in an updated schedule. For more on how depreciation schedules work in practice, see our detailed guide on Property Depreciation Schedules Explained.
Investors should also be aware of the interaction between depreciation and capital gains tax. Depreciation deductions claimed under Division 43 reduce the cost base of the property for CGT purposes, which increases the taxable capital gain on eventual sale. Division 40 deductions on plant and equipment do not affect the property's CGT cost base in the same way — the assets are treated separately. This interplay between annual depreciation benefits and the eventual CGT outcome should be factored into any long-term investment modelling. For a broader view of how tax and property wealth-building interact, WealthWatchPro's retirement and tax planning hub offers supplementary context on structuring property assets within a broader financial plan.
Practical Steps: Maximising Your Depreciation Position
The most effective way to maximise depreciation deductions is to commission a depreciation schedule from a registered quantity surveyor before lodging your first tax return on any investment property. This applies regardless of whether the property is new or established — even if Division 40 deductions are restricted on second-hand plant and equipment, the Division 43 capital works deduction remains available on eligible buildings, and many investors overlook this because the deduction is less immediately visible. A qualified surveyor will identify every claimable item and apply the correct effective life schedule to each asset.
Investors undertaking renovations should keep detailed records of all construction expenditure, including contractor invoices, materials receipts, and council-approved plans. These records form the basis of the new Division 43 schedule for the renovated works. Any new plant and equipment installed during a renovation — new kitchen appliances, new air-conditioning, new hot water systems — creates fresh Division 40 entitlements that can be depreciated from the date of installation.
SMSF investors face additional complexity. Where an SMSF holds residential property, the same depreciation rules apply for tax purposes, but the SMSF's concessional tax rate of 15% changes the effective value of each deduction compared with an individual investor's marginal rate. High-income investors in the top marginal bracket benefit most from depreciation deductions on an after-tax basis, since each dollar of deduction offsets income taxed at a higher rate. For a detailed walkthrough of how these rules connect to property tax planning more broadly, our Australian Property Tax Guide covers the full framework. Landlords should also consider that insurance premiums on investment properties — explained in our Landlord Insurance in Australia — Complete Guide — are separately deductible operating expenses, distinct from the capital-based depreciation framework covered here.
Understanding the distinction between Division 40 and Division 43 is not a matter of fine print — it determines which assets you can claim, at what rate, and for how long. Investors who treat depreciation as an afterthought routinely leave legally available deductions unclaimed. A properly prepared schedule, reviewed annually and updated after any capital works, is one of the simplest ways to improve the after-tax return on any Australian investment property.
This article was produced with AI assistance and reviewed for accuracy. Content is for informational purposes only and does not constitute financial or property investment advice.
