Granny flats: tax tips and traps

With more older Australians looking to downsize and younger generations eager to get a foot on the property ladder, building a granny flat or a second dwelling in your backyard has become an increasingly popular and affordable solution.

This guide covers the tax angle below, then walks through the Centrelink rules, deprivation provisions, and aged care interaction that families often miss.

In 2023, a CoreLogic analysis of residential properties in Sydney, Melbourne, and Brisbane, identified more than 655,000 sites suitable for constructing a granny flat. The demand has grown so much that numerous businesses now offer modular buildings as an alternative to designing and constructing a custom build.

Before taking the leap, be sure to check local council regulations, restrictions, and permit costs. Rules vary between councils and typically include limitations on size and location.

Granny flat arrangements and the family home

A granny flat arrangement is where a parent transfers ownership of the family home (or pays for a right to live in a child’s home) in exchange for a lifetime right of accommodation.

Done properly, it can be a legitimate way to preserve family wealth and keep an ageing parent close to loved ones. Done poorly, it can trigger Centrelink deprivation rules, capital gains tax issues, and family disputes.

The Centrelink rules around granny flat interests are technical, and the “reasonableness test” determines whether the arrangement is treated as a gift or a genuine transfer of value.

If you are considering this path, get advice before any money or title changes hands.

Granny flat tax implications

It’s also important to know there are potential tax implications, particularly capital gains tax (CGT).

While a granny flat may be considered a secondary dwelling on a property, eligibility for a main residence CGT exemption requires a written agreement granting someone the right to occupy the property for life. This agreement can be made with any party, including family or friends, and will be exempt from CGT provided the person with the ‘granny flat interest’ has reached pension age or requires assistance with daily activities due to a disability.

Granny flat or investment property?

There are important differences between a granny flat arrangement, building a secondary dwelling on your property as an investment, and renting out a room in your home.

A second dwelling on your property used for short- or long-term rental purposes is considered a commercial arrangement. The rent you receive is assessable income and is taxed at your marginal rate.

As with most income-producing activities, you are entitled to claim the usual expense deductions against the rental income.

Granny flat arrangements, on the other hand, must not be commercial in nature.

Capital gains

Capital gains tax (CGT) can be a key consideration when setting up a granny flat arrangement. If you don’t follow the rules, you may face an unexpected tax bill when you eventually sell your home.

Generally, a granny flat arrangement is exempt from CGT, provided it is not commercial in nature and there is a written granny flat arrangement.

This means that if the person living in the granny flat makes payments at market rates, such as rent, CGT will apply. However, if they only contribute to ongoing household costs, such as electricity and water, the ATO is unlikely to consider it a commercial arrangement.

To qualify for the CGT exemption, the property owner must be an individual, at least one person must hold an eligible granny flat interest in the property, and both parties must have entered into a written and binding granny flat arrangement.

The CGT exemption applies only to the creation, variation, or termination of a granny flat arrangement.

Other CGT events unrelated to the arrangement remain subject to standard CGT rules.

Tips for successful arrangement

While adding another dwelling to your property may increase its value, it’s essential to bring all parties together to discuss potential future scenarios before signing the written agreement. This helps prevent issues further down the track.

The agreement should outline who is involved, the circumstances under which it can be varied or terminated, and what happens if such a situation arises.

It’s also wise to discuss how any disputes or financial conflicts will be resolved and to seek professional legal advice before signing.

If you or someone you know is considering a granny flat arrangement, our expert financial advisers can help you understand the tax rules, key considerations, and how it fits with your financial situation and goals.

What is a granny flat interest?

Beyond the tax rules sits the Centrelink side of the conversation, which often matters just as much for families thinking about aged care or pension entitlements.

In Centrelink terms, a granny flat interest is a life interest or a right to accommodation created when a person transfers assets (typically cash or the family home) to someone else in exchange for the right to live in a property for the rest of their life.

The name is a little misleading. It does not have to involve a physical granny flat out the back. The arrangement can take several forms, including:

• Transferring the family home to an adult child and continuing to live in it.
• Paying for an extension, renovation, or self-contained unit on a child’s property in exchange for the right to live there.
• Buying a new property in a child’s name and retaining a life interest over it.

When Centrelink accepts the arrangement as a valid granny flat interest, the transferred asset is not counted as a deprived asset, and the person’s assessable assets are adjusted based on the “reasonableness” of the amount handed over.

In other words, a properly structured granny flat right can have age pension benefits, but only if the arrangement stacks up against Centrelink’s rules.

How Centrelink assesses a granny flat interest

The heart of the assessment is the “reasonableness test”. Centrelink compares the value of what has been transferred (for example, the family home or a lump sum) against the value of the accommodation right the person is receiving in return.

If the amount handed over is considered reasonable for the right to live in the property for life, Centrelink treats it as a genuine granny flat interest and does not apply deprivation provisions.

If the amount transferred exceeds what Centrelink considers reasonable, the excess may be treated as a deprived asset, which is where things start to hurt.

To work out what is reasonable, Centrelink calculates an “entry contribution” using the person’s age at the time of the arrangement and a set of actuarial conversion factors.

The logic is straightforward, even if the numbers are not. The older the person, the shorter the expected period of occupancy, so the lower the reasonable value of the life interest. A 65-year-old has a much higher reasonable amount than an 85-year-old doing the same thing.

Because the calculation depends on age and current figures, it is worth modelling the numbers carefully before committing. Small differences in valuation or timing can shift the result from a clean arrangement to one that triggers deprivation.

Deprivation rules: what happens if you get it wrong?

If the value of what has been transferred exceeds the reasonable amount for the granny flat interest, Centrelink treats the excess as a gift, and the gifting rules kick in.

Under current rules, gifts above $10,000 in a single financial year, or $30,000 across any five-year period, are treated as deprived assets. Deprived assets continue to count towards the assets test and income test for five years from the date of the gift, even though the person no longer owns them.

The result can be brutal. The person has given away the asset, so they no longer control it, but Centrelink still counts it against them for pension and aged care purposes.

Families have contacted our team for support after transferring a $1 million home to a child, once discovering that a large chunk of it is treated as a deprived asset, quietly reducing their pension for the next five years. It is rarely fixable after the fact.

Granny flat interests and aged care

A granny flat arrangement often gets set up years before aged care becomes a real conversation, which is where the timing risk sits. When the person with the granny flat interest eventually needs to move into residential aged care, the interest  ceases because they are no longer living in the property unless their spouse continues to live there.

At that point, the asset that was previously excluded (or only partially counted) may come back into the assessment, depending on timing and whether the need for aged care could have been forseen.

If deprivation rules were triggered when the transfer happened, the deemed asset continues to count for the remainder of the five-year deprivation period, which can affect both the age pension and the aged care fees that are means tested particularly whether there is government support to help pay for accommodation.

For families weighing up how to fund aged care, this can affect the conversation around the accommodation decision and whether a support at home package is a better bridge in the meantime.

When a granny flat arrangement makes sense

Used in the right circumstances, a granny flat interest can be a legitimate and effective strategy. It tends to work best when:

• The parent is relatively young at the time of the arrangement, so the reasonable amount is higher.
• The value of the property (or the contribution) is not wildly above the reasonable threshold.
• The family has worked through the CGT, stamp duty, and land tax costs, and they are manageable.
• The arrangement is documented properly with a formal legal agreement, not a handshake deal.
• There is a sensible backup plan if the parent needs aged care sooner than anyone expects.
• Other planning is in place, such as an enduring power of attorney, so decisions can still be made if capacity is lost.

Proper legal and financial advice is essential before any money moves or any title changes hands.

How Alteris can help

Alteris takes a multi-disciplinary view of granny flat arrangements. That means modelling the Centrelink assessment,  identifying the CGT and stamp duty consequences, and stress-testing the aged care implications before the family commits to anything.

We work alongside your solicitor to make sure the legal documentation reflects what Centrelink actually wants to see, so the arrangement holds up under assessment.

Every family situation is different, and the same arrangement that works beautifully for one household can cause real problems for another. We would rather run the numbers with you first than help clean up the mess later.

Frequently asked questions

Does a granny flat interest protect the home from aged care fees?

Not automatically. A properly structured granny flat interest that meets the Centrelink rules does not make the home invisible to the aged care means test. If the person later enters care within 5 years, the asset may still be counted, depending on circumstances. Professional advice is essential before assuming the home is “safe”.

Can I set up a granny flat interest after entering aged care?

No. A granny flat interest requires the person to actually be living in the property, so once someone has moved into residential aged care the arrangement can no longer be established. This is one of the main reasons we push families to think about these questions early, rather than when a health event forces a decision.

Is a granny flat interest the same as a life interest?

They are related but not identical. A Life Interest or a Right to Reside is a legal interest in property that gives the holder the right to live there for life. A granny flat interest is the Centrelink term for an arrangement where assets are exchanged for accommodation rights.

What if my child wants to sell the property while I’m still living there?

This is one of the real risks, and it is why documentation matters. If the arrangement is only a handshake, the parent has limited legal protection if relationships change or the child’s circumstances shift. A properly drafted granny flat agreement or life estate gives the parent enforceable rights, which is why we always recommend involving a solicitor alongside the financial planning work.

This article is general information only and does not take into account your personal circumstances. Aged care, Centrelink, and tax rules change frequently, and the strategies discussed here may not be appropriate for every family. You should seek personal advice from a qualified financial adviser, accountant, and solicitor before acting on the information contained in this article. Figures referenced in this article are current as at the date of publication and may be subject to change. Alteris Financial Group is licensed to provide personal financial advice in Australia and works with families across the country on aged care, retirement, and intergenerational wealth strategies.

Sources:

i Untapped granny flat potential in largest capitals could boost housing supply | CoreLogic Australia

ii Granny flat arrangements and CGT | Australian Taxation Office