Granny Flat Interest Calculator
Model the social security value of a lifetime accommodation interest.
Enter the Accommodation Arrangement
Apply the Published Assessment Method
Relative’s existing home; home-only transfer/build; or a special social security advantage case.
A relative’s home means an existing relative-owned home. Transfer, purchase or build covers the home only. The special advantage case is a special social security advantage case.
The annual rate is the combined partnered rate even for a single person. For historical matters, use the rate at establishment. This worksheet calculates locally and does not save your entries.
Enter the full value transferred for accommodation, including any extra assets. An accommodation interest gives a lifetime right to live in a private principal home. Retaining title creates an ownership interest that requires a different assessment.
An investment property held for rent falls outside this model. A self-contained building is not required for a granny flat interest.
The DSS conversion-factor method multiplies the combined annual partnered pension rate at establishment by the age-next-birthday factor. Couples use the younger partner’s age. The same combined rate applies to single people.
The table starts at age next birthday 51. A person aged 79 at establishment uses 80 and a factor of 10.04. Ages above 100 keep the factor 2.60. This tool stops when the relevant age next birthday is below 51.
For the hypothetical defaults, $40,000 multiplied by 10.04 gives $401,600. The $450,000 payment for existing accommodation produces a modelled interest of $401,600 and a $48,400 difference.
The DSS arrangement rules generally accept the amount paid for a home transfer, purchase in another person’s name or construction without extra assets. For these ordinary cases, the calculator shows the reasonableness amount for comparison only.
For a home transfer or construction plus extra assets, the published rule uses the greater of the home or construction value and the reasonableness amount. Existing relative-owned accommodation uses the payment up to the reasonableness amount. A special social security advantage case uses the reasonableness amount.
In the DSS example, a $280,000 home plus $100,000 of extra assets totals $380,000. With a $310,000 reasonableness amount, the interest is $310,000 and the difference is $70,000.
Assessment periods change the pension rate used. A birthday changes the conversion factor. Enter the facts at establishment together so the model does not mix today’s age with a historical payment.
Read the Result Alongside the Evidence
A positive difference shows the amount above the modelled interest, before a separate gifting assessment. A negative difference means the published model value exceeds the payment.
This calculator models administrative social security arithmetic. Its result does not establish market value, legal enforceability or whether a transfer involved elder abuse.
Match the bank transfers and transferred-asset valuations to the signed accommodation agreement. Obtain title records and construction invoices where those facts decide the valuation branch. Confirm the lifetime right, principal-home use and ages at establishment.
Keep the establishment-date rate record with the scenario. The Services Australia pension rate table separates basic pension and supplements. The calculator takes an entered annual assessment rate and does not select components from a payment total.
Additional granny flat rules cover entry contributions, multiple interests and leaving accommodation. This tool does not calculate pension entitlement, homeowner status or gifting exemptions. Multiple interests and interests established before the supported date require a different assessment.
Use the granny flat interest guide to interpret the accommodation concept alongside the agreement and transfer evidence.