It may surprise you: the more expensive property can be the cheaper one to hold. So here is a real comparison: three new homes in the same estate in Tweed Heads, priced in October 2026. A single home, a dual income home on the same size block, and a duplex. Prices and rent appraisals are as at August and October 2026, and the principle holds for any homes like them.
Tweed Heads is one example. We work Australia-wide, and the same comparison can be run on homes in any state or territory.
The three homes
| Single home | Dual income home | Duplex | |
|---|---|---|---|
| What it is | 4 bed, one household | 6 bed, two self‑contained homes | Two attached homes, one title |
| Floor area | 198 m² | 254 m² | 364 m² |
| Block | 520 m² | 520 m² | 616 m² |
| Package price | $1,332,949 | $1,471,177 | $1,877,089 |
| Rent, appraised | $1,300 to $1,350 a week | $1,900 to $2,000 a week | $2,200 to $2,300 a week |
| Gross yield | about 5.2% | about 6.9% | about 6.2% |
All three are new, finished to move-in condition, with a full depreciation schedule ahead of them. As new builds, all three keep negative gearing from the 2027-28 income year for their first owner. The single home and the dual income home sit on the same size block, so the land is the same. The difference is what is built on it.
Spending more, paying less
The dual income home costs about $138,000 more than the single home. It earns about $32,500 a year more rent. At today’s rates, the interest on that extra $138,000 is about $9,900 a year. After running costs, the extra rent covers the interest on the extra borrowing more than two and a half times over.
Here is each home with every dollar borrowed, as it would be if the deposit came from equity in another property, before tax and depreciation:
| Before tax, all borrowed | Single home | Dual income home | Duplex |
|---|---|---|---|
| Rent after running costs | $55,120 a year | $81,120 a year | $93,600 a year |
| Interest only at 7.14% | $95,173 a year | $105,042 a year | $134,024 a year |
| Cost to hold, each week | about $770 | about $460 | about $777 |
| Years until rent covers the interest | 11 | 6 | 8 |
The home that cost $138,000 more costs about $310 a week less to hold, and its rent catches the interest five years sooner. With a 20 per cent cash deposit instead, the dual income home comes within about $56 a week of carrying itself before tax, while the single home still costs about $404 a week. Tax deductions and depreciation reduce the cost of all three further, and the homes with more building in them have more to claim.
When the market doubles
History is a rear-view mirror, not a forecast. Between December 1991 and December 2021, Australian dwelling values rose about 381 per cent by CoreLogic’s figures: they more than doubled, then doubled again, in thirty years. Sometimes it happens sooner, when inflation runs high, and sometimes later, when it runs low. On that history, I’d expect real estate to double again, sooner or later.
Take two properties, one dearer than the other. When values double, each gains what it was worth, so the dearer one gains more in dollars. If the dearer one also cost less each week to hold while it grew, spending more has meant paying less. And if the deposit was borrowed, the extra was bought with interest, not savings.
No one can tell you the year the market will double again. History suggests it will, though history is not a promise for any one property.
Who this does not suit
A dual income home means managing two tenancies, and a duplex two homes. Every figure here depends on the rent being achieved and the loan rate holding near today’s. And a bigger loan is a bigger commitment through the years when values fall as well as rise. The right choice depends on what you hold already, what you earn and how long you can carry the cost, and that is worth modelling before anything is signed.
To see how the three compare against your own numbers, book a first conversation. It costs nothing, and you will be told plainly whether there is value to add.
Nicholas Lockhart
Prices and rental appraisals are from the estate’s price list of August 2026, unchanged on its October 2026 list. Assumptions, disclosed: every dollar borrowed interest only at 7.14 per cent (Canstar average investor variable interest-only rate, 2 October 2026), or 80 per cent where stated; rent at the midpoint of each appraisal; running costs of 20 per cent of rent covering management, rates, insurance, maintenance and vacancy; rent rising 6 per cent a year, MRD’s standing modelling assumption, for the years‑to‑cover figure (MRD estimate). Tax and depreciation are left out of the tables. The doubling example is general, not a forecast for these homes.
Sources: Canstar, average home loan interest rates, 2 October 2026; CoreLogic Home Value Index, December 1991 to December 2021, published 21 March 2022.