What’s a Duplex House – Everything You Need to Know

October 8, 2021
duplex house red brick facade

If you’re looking to buy a home, you’ve likely asked yourself what a duplex house is and how it works exactly. The duplex has recently grown in popularity to rank next to townhouses and apartments as a decent, affordable type of property to live in. 

Duplexes certainly have their advantages whether you own the whole house or just one half of it. From renting it out to turning the other half into your home office, there are many ways to profit from investing in one. And if you’re simply living in the one half, you’re able to live in a desirable location at a reduced price. 

So before we get into the pros and cons of the duplex, let’s discuss its typical characteristics.

What is a duplex?

rendering of duplex house

A duplex is a residence on a single block that has two separate homes sharing the same central wall. They are contained in one building and can either be split into two separate titles or be coupled together. They can also be owned and sold under one land title. 

Each home will be its own dwelling, with bedrooms, bathrooms, kitchens and even garages split. Often, the mailing address will be split as well. 

If you’re the owner of a duplex, you will have a building insurance policy for both sides of the duplex, even if they’re under the same roof. 

Although it’s less common, some duplexes in some states will require a body corporate. So if you’re interested in finding out more, we suggest contacting the local authority in your state. 

What’s the difference between a freestanding house and a duplex?

Put simply, a house is one single residence whereas a duplex is two. While the commonality is that they both have one single roof, the duplex will have two entrances and separate amenities.

Should I buy a duplex house?

large free standing house in suburb
Free standing house

There are definite benefits to buying a duplex. For buyers, it can be a more affordable way to enter the property market, particularly in a sought-after neighbourhood which has otherwise high housing prices. 

With median property prices rising in Australia’s capital cities, duplexes can be a safe, sound investment. If your dream is to live on a landed property, but you’re still building the budget, duplex properties offer several of the advantages at a portion of the price

As an investor, you can gain from two rental incomes instead of the one from a single home. While the rental payments might be lower, the double income still beats the one. And if you’re building a duplex, the investments you put in for land and construction won’t be as high. Since the two duplex units share a common wall, the costs are much lower than for two separate houses. 

Duplex homes can also function much like a granny flat. While the granny flat involves a completely separate unit, the duplex allows for the sharing of a wall, which may be a better fit for older relatives needing to live in close proximity. A suitable choice for multi-generational family homes.

You can find more duplex options as a second unit in Sydney, Brisbane and the Sunshine Coast. Many owners have discovered the value in renting out the other half for extra income. So while you have the privacy of your own home, you also benefit from the security of a close, next door neighbour

If you work remotely, this may also be a great option for you. With more of us working from home these days, the other half of a duplex could serve as the ideal office. There’s even the possibility of renting out the remaining rooms to others in your neighbourhood who are working from home as well. 

Can I own half a duplex house?

Yes, you can own half. And you can also own both dwellings. It depends on whether both residences share the same title or if they’ve been subdivided into two different titles

What types of duplexes are there?

beautiful interior of house

The design of a duplex can be flexible and usually depend on the lot of land. Some blocks can fit two units side by side, while others have a top and bottom configuration, or a front and back. They can have two storeys more traditionally, but even three storeys are not unheard of. This depends on your council and state regulations.

Is it better than an apartment?

In certain ways, a duplex may be better than an apartment. They are usually larger in square footage for the price you’re paying. 

In an apartment, you’ll also likely have more shared walls and therefore, more neighbours. Also, apartment buildings may offer more options in amenities, while the duplex’s amenities will likely be in-house. 

How do I build one?

If you’re convinced that building a duplex is right for you, then there are a few other things you need to consider first. While there are several approved and trustworthy builders out there who can advise you on construction, it isn’t like the standard house. When you’re designing a duplex, you should consider different important elements like:

  • Land – what kind of duplex build does this land support?
  • Configuration – does this layout allow for maximum privacy between the two residences?
  • Natural light – because the duplex has a common wall component, this closes you off to an entire aspect of light. But you can build the duplex to maximise as much natural light as possible. 
  • Layout – do you want two identical dwellings? You may want one bigger than the other.
  • Entrances & facade – how do you want the two separate entrances—side by side? How do you want the front, sides and backs to look?

Cons of living in a duplex

neighbour fencing

Since we’ve touted the pros of living and investing in a duplex, we think it’s also important to highlight the potential pitfalls


While you have your own home to yourself, the one wall can be an issue. If you and your neighbour are buddies, then no problem. But if you aren’t close, then there’s the potential of noise complaints from being “too close for comfort” or fencing issues or pets.

Bad layout

This is something to keep in mind if you’re choosing to live in one half of the duplex, or building a duplex from scratch. For instance, if the duplex is built in a front and back layout, this might mean your neighbours have to pass by your bedroom at inconvenient times to access their home.


Don’t forget that while an investment may yield double rental income, it also means double the maintenance taking care of your tenants. As a landlord, you should also be prepared to experience periods with no renters at all. 


If you’re living in one of the duplex units, you may be limited in terms of what you can change in the home. Since the entire duplex is under one strata title, revamping the facade might not be an option for you. 

There are so many different property types out there. If you’re not sure what kind of home you want to live in just yet, keep browsing through our listings on Soho. And get registered here so we can learn what you like and improve your property matches. 

Join Soho for free, the new way to discover and swipe your dream home, connect to experts in the real estate community and stay updated with market trends when you are buying, renting or selling property.
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