High-Growth Properties and the 2027 CGT Rules: How Much More Tax Will You Pay?

If your investment property has been growing at 6% or more per year, the 2027 CGT reform is going to cost you. The question is just how much, and what (if anything) to do about it. Treasury's own worked example for Kate a $500,000 property growing at 7.5% per year for ten years shows $58,851 of additional tax payable compared to the current 50% discount. For owners of Sydney and Melbourne houses in high-growth corridors, who routinely see 7-10% annual capital growth over long holding periods, the numbers can run into the hundreds of thousands of dollars on eventual sale.

This article walks through exactly how the reform affects high-growth property, the maths behind the additional tax, and the strategic decisions investors should weigh in 2026 and 2027 including the question of whether to sell before 1 July 2027.

Why high-growth property loses out

Two effects work against high-growth investors under the new system:

1. Loss of the 50% discount. Under the old rules, half of a nominal gain escaped tax entirely. Under the new rules, only the inflationary portion (around 2.5% per year compounded) escapes tax through indexation.
2. The gap widens with growth. The faster your property appreciates relative to inflation, the larger your real gain and therefore the larger the taxable amount under the new regime. The 50% discount was indifferent to real vs nominal; indexation is not.

Kate and Jane: the high-growth Treasury examples

Kate $500K asset, 7.5% growth, 10 years

Final value approximately $1.03 million. Nominal gain $530,000.

• Old 50% discount: Discounted gain $265,000. Tax at 47% marginal rate = $124,550.
• New indexed regime: Indexed cost base $640,000. Indexed gain $390,000. Tax at 47% = $183,300.
• Difference: $58,851 more tax under the new rules.

Jane transitional case, $800K asset, 7.2% growth, 10 years

Jane bought before 1 July 2027 (in 2022) and sells after (in 2032). The pre-2027 gain attracts the old 50% discount; the post-2027 gain uses the new indexed regime.

• 1 July 2027 value (apportionment): $1,131,371.
• Pre-2027 taxable gain (after 50% discount): $165,685.
• Post-2027 taxable gain (indexed): $319,958.
• Total taxable: $485,643. Tax at 47%: $228,252.
• Under old rules on full holding: tax would have been $188,000.
• Difference: $40,252 more tax.

Sydney and Melbourne implications

Long-term capital growth for established Sydney inner-suburb houses has averaged 6-8% per annum over the past 25 years. Melbourne inner-city houses have been similar and many of the locations on our best suburbs to invest in 2026 list sit squarely in the bracket where the new rules sting hardest. For investors in these markets:

• The new rules increase CGT meaningfully on every $100,000 of post-2027 gain.
• Long-held properties (15+ years) face the largest absolute additional tax bills.
• The 1 July 2027 valuation is the most important number get it formally done.

Should you sell before 1 July 2027?

This is the most-asked question and there is no single answer. The decision turns on:

Arguments for selling before 1 July 2027

• The entire gain attracts the old 50% discount no indexation, no 30% floor.
• You crystallise the tax outcome rather than betting on future market conditions.
• You free capital for redeployment into other strategies.
• You avoid the administrative burden of the 1 July 2027 valuation.

Arguments against selling

• Transaction costs. Agent's commission (1.5-3%) plus stamp duty if you rebuy elsewhere can wipe out the tax saving.
• Forgone future growth. If the property continues to grow at 7%+, the additional pre-tax wealth created by holding can substantially exceed the additional CGT.
• Inability to repurchase. A strong market may not allow you to buy back a similar property at a similar price after selling.
• Market timing risk. Forced sales into the same six-month window may depress prices.

The break-even calculation

A rough heuristic: if you can earn more than the additional tax cost in capital growth by continuing to hold, holding wins. For Kate's property (additional $58,851 tax), if her property is worth $1 million in 2027 and grows at 5% in nominal terms thereafter, she earns $50,000 in her first year of holding already offsetting most of the additional tax. Selling generally only makes sense if you were planning to sell soon anyway.

The 30% minimum tax interaction

For high-growth properties, the 30% minimum tax rarely binds because the gains are so large that they push you into top marginal territory (47%) regardless of other income. The 30% floor is more relevant to low-income investors with mid-sized gains. High-net-worth investors typically pay well above 30% on their gains in any case.

Using capital losses to offset

Capital losses continue to offset capital gains under the new rules. Investors with carry-forward losses from prior years can apply them to reduce taxable gains. Some strategies to consider:

• Loss harvesting in 2027. Sell underperforming shares or properties at a loss in the 2026-27 financial year to create losses available against future gains.
• Coordinated sales. Pair a large taxable gain with the disposal of a loss-making asset in the same financial year.
• Trust planning. Where losses are trapped in one entity and gains in another, structural advice from a tax specialist may unlock value.

What high-growth investors should do now

1. Get a current professional valuation. Know what your property is worth today it informs the sell-or-hold decision.
2. Model both scenarios with your accountant. Sell now vs hold and pay CGT later. Use realistic assumptions about future growth.
3. Commission the 1 July 2027 valuation in mid-2027. For high-value assets, a formal valuation is excellent value.
4. Review your overall portfolio. The reform may shift the relative attractiveness of property vs shares vs super contributions.
5. Avoid panic. Most rushed property sales destroy value. The reform announces a structural change but does not abolish CGT-efficient property investing.

This article provides general information about the 2026-27 Federal Budget CGT reform measures announced for commencement on 1 July 2027 and is not financial, tax or legal advice. Tax outcomes depend on individual circumstances. Always consult a registered tax agent, financial adviser or the Australian Taxation Office before acting. Treasury factsheets and the official Budget Papers remain the authoritative source.