Your home is the culmination of your ambition, financial efforts and ingenuity. It is, for many reasons, the most important investment in your life, and in times of financial woes, it can act as a lifeline that will regulate your family’s economic situation and potentially even bring you a substantial income. But as you are probably feeling first-hand, Australian houses have a slight issue. They are ridiculously expensive, and if your current dwelling no longer fits the growing demand of your family, or you need more space for day-to-day activities, you will be stuck between a rock and a hard place.

What exactly can you do when the current housing situation in NSW is no longer suitable for the finances of most families? What if you need to move into a more spacious unit, or you simply want to be closer to schools, shopping malls, or your workplace? Well, for many, the solution is investing in the expertise of duplex home builders, who specialise in the design and construction of semi-detached houses. Duplexes, alongside ADUs, are one of the best solutions for families looking for the best real-estate deal on the market, as basically, these types of constructions come in the form of a 2-1 package.

With a duplex, you receive not only the benefits of a single detached unit. You pretty much gain two houses for the price of one. The yields made possible by duplex home builders are, on average, around 15-20% greater than with conventional properties, and that’s because, for the most part, their construction is a bit more straightforward. The shared walls, the separate utilities, the foundation, plus the shared maintenance cost make duplexes a better long-term deal for families looking for the best bang for the buck.

It's A No-Brainer When It Comes to Costs And ROI

The median cost of Sydney-listed properties has now reached the stunning value of $1.5 million. These sums are pretty much impossible to deal with for the vast majority of Aussie families without access to long-term financial packages like mortgages, and therefore, the market, at least in the last couple of years has seen the rise of alternative living units, such as ADUs, and duplex constructions. They are cheaper, they require ( for the most part) less paperwork, and they can also potentially be rented out as a source of secondary income.

Let’s say, for example, that you are interested in buying an R2 low-density residential lot in a suburb of western Sydney like Parramatta. Most likely, the land you are interested in will be available for less than $1 mil, and after that, the construction of the duplex, if we are talking about a unit with two baths and four bedrooms, will cost around $800,000. It’s a lot of money, that’s true. But a detached house will likely cost you just as much. The difference lies in when and if you decide to sell your unit. The constructions finalised by duplex builders in Sydney can be sold separately, and thus increase the final yield of the real estate investment.

There Is a Reason Why Business Is Growing for Duplex Home Builders

Considering that the median unit price in NSW, as of January 2026, has now surpassed the value of $950,000, your ROI, after the construction is finalised, if you decide to sell, and  if we don’t consider the price of the land, will be closer to 100%. If we take into consideration the costs associated with the purchase of the plot of land, you will most likely break even. But there is an asterisk here. The real estate market in NSW grows by around 5% per year.

So, in practice, once the construction made possible by the duplex builders in Sydney is finished, it will most definitely bring you a profit. But one should also mention the potential rental income. The average median rent for a unit close to the CBD is somewhere around $750 per week. Potentially even more depending on area and nearby attractions. In rental income, that will amount to around $39,000 per year, assuming you manage to benefit from an occupancy rate close to 100%.

The gross rental yield of NSW units, if the property costs you around $800k, will be around 4.5% per year, while the net yield can be closer to 3.5%. It’s not a huge sum, that’s true, but remember that your initial investment will likely pay off when you decide to sell. The properties designed by duplex home builders, just like with granny flats, make sense if you plan to use them as secondary dwelling units, for rental purposes, or simply for increasing your usable living quarters.

It's A More Flexible Living Situation

Besides the obvious rental benefits, the semi-detached buildings made possible by the expertise of duplex home builders are a good way to adapt your living conditions to your family’s space requirements. In practice, this means that duplexes can always act as an option if you decide you need more space for daily activities, or if you require a separate living space for some of your visiting family members.

With a duplex, you can live in a unit and rent the other out, do so for both, or even sell one and continue living in the other, either temporarily or permanently. Plus, just like with granny flats, semi-detached houses designed by duplex builders are perfect for multi-generational living and are more resilient to zonal modifications or changes imposed by local councils.

The documentation required for their construction is, however, more involved. While granny flats can often be developed only with a CDC, semi-detached houses designed by duplex builders often necessitate a DA, which will require an SEE, a BASIX certificate, a site survey plan, and of course, a CCD and OC (if you plan to lease the duplex). The process can be involved, but the results, at least from a financial standpoint, will almost surely be worth it.