What Is The Difference Between Dual Occupancy And Duplex?

occupancy melbourne

The property of dual occupancy represents a typical property where the piece of land retains one title and has two types of dwellings that are constructed on it. The version of dual occupancy is alternatively known as multi-dwelling, whereas, a duplex or ‘side-by-side’ house is a type of construction that has two features in the same area. With these, this arrangement brings upon maximum flexibility and a tendency of full potential returns from a land parcel. These types of properties are then consolidated under the same version of the title and then reaped for a better return on certain investments when compared to two separate houses.

We all have heard about the duplex and dual occupancy homes. If you are still scratching your head for the difference between duplex vs dual occupancy home designs and getting confused between its similarities in its difference, you have come to imbibe the right article.

Many times, people may refer to one as the other, and this can complicate the matter in identifying the difference but pointing out in terms of which one is who is quite simple- One can narrow it down to these smaller things.

Duplex homes are by law classified as a dual occupancy meaning, “two dwellings on one title, either attached or detached”. They are different from having a secondary dwelling or granny flat situated at the back of a property.

Attached dual occupancy means two dwellings on one lot of land that is attached, but does not include a secondary dwelling.

Detached dual occupancy means two detached dwellings on one lot of land but does not include a secondary dwelling.

Dual Occupancy, Duplex and granny flat. You’ve probably heard of all these terms. But even though they all differ from one another, these three types of dwellings are often confused. When building a new house, it is helpful to know what they are. To find out whether one of them might be an option for you, we have created a short and comprehensive guide with all the right points to consider:

duplex homes

Dual Occupancy

Dual occupancies, also known as shared-living homes, exist in two versions – attached and detached. However, the land they are built on is always considered one piece of land and can not be subdivided. While it can limit your liberties, it often means lower building and council costs compared to a duplex. Utilities for the dwelling can be separated though.

Dual occupancy is ideal for first-home buyers, who are on a budget but still value a good neighbourhood and aesthetic housing since it will cost you significantly less to acquire a dual occupancy than buying a single-family house.

When building a new house, remember:

  • also known as shared-living homes
  • can’t be subdivided -> less building and council cost
  • separate utilities possible


A duplex often looks just like a dual occupancy. But even though the two households share a wall, often referred to as a common ‘party wall’, they are considered two dwellings. They are therefore listed with separate titles, which is why the land can be subdivided. As the possibility to subdivide exists, a duplex offers more liberties as to buying and selling a house than a dual occupancy does. Another benefit to the duplex is its price. You will pay up to half of what a single-detached house, same style and size, would cost you, which is why the Duplex is very popular among first-home buyers as well. At MJS Construction Group, we have the best dual occupancy selection to make your house a dream come true.

When building a new house, remember:

  • two separate dwellings with separate titles -> can be subdivided
  • common ‘party wall.’

Granny Flat

A granny flat can be defined as a self-contained home extension to a principal dwelling. It usually contains a bedroom with a bathroom, as well as a small kitchen, dining and a living area. The flat can either be attached to the main house, separated through, e.g. a garage or fully detached. Local councils dictate the size but in most cases doesn’t exceed 60 square metres.

Granny flats are, as their name suggests, popular among ageing parents or grandparents. They can still live independently but have their family in closest proximity. And also for teenage children moving out for the first time, this type of dwelling can be a fitting option. Another way to make use of a granny flat and at the same time get extra income for the household is to rent the flat out, as they are popular accommodations.

When building a new house, remember:

  • self-contained conjunction to a principal dwelling
  • often occupied by independent family members

Learning The Difference Between Duplex Vs Dual Occupancy Homes

Starting with bifurcating the difference of a dual occupancy home is that it should be under a single land title. A dual occupancy home allows one to be more lenient as compared to its lot size of a duplex.

This even affects the pricing of a duplex with the list of a dual occupancy home. The cost evaluation of a duplex building would be costlier than that of a dual occupancy home. On the contrary, a dual occupancy project comes with its own set of challenges and hurdles. A dual occupancy builder has to fit all the features and comfort of a home into a compact and smaller sized land and space along with floor space of the property. The limitation of the space also means that one has to create a more prominent space for each resident. With that being jotted down, a dual occupancy designer also procures more benefits than others, just like building a secondary home, i.e. a granny flat and it is because of its occupancy on a single land and its construction makes one rent the other occupancy on rent. The rent one acquires from a dual occupancy home is much higher than as one has to sublet a granny flat. When meeting certain criteria, subdividing dual occupancy homes is made possible and can be considered as to sell a dual occupancy home.

Understanding A Duplex Home

A single building, divided into two separate dwellings under one roof is known as a duplex. The main difference between a duplex and a dual occupancy home is its land flexibility. Since the duplex is under one land title, one can sell the homes altogether, and it can also be set under two land titles. This means one can sell their homes separately. The construction of duplex requires a certain sized block and also a wide piece of land for a dual frontage such as corner block. The requirement of land is of a higher standard than a dual occupancy; hence, the price of buying land is a lot higher. Because of this, the purpose of constructing the duplex and design is costlier, and duplexes usually go on higher rental for better income.

Why Should You Build A Duplex?

If you currently have a knock-down rebuild and want to build two new dwellings, or want to build a new dwelling behind an existing one or two new dwellings on a vacant block of land, you won’t go wrong with a duplex.

Duplex homes are becoming increasingly popular among homeowners who want to maximise their income, downsize their current home or increase the value of their property. Besides,a duplex home can often be subdivided whereas, a secondary dwelling or granny flat cannot. Once a dual occupancy is subdivided, one or both of the dwellings can be sold, reducing debt levels.

There Are Many Benefits To Having A Dual Occupancy, Such As:

The increasing value of property

With building a duplex, for example, there is potential to increase your property up to 40% and if a dual occupancy subdivision can be achieved there is potential for properties to double in value.

An additional source of income

Supplementary to regular salaries, the rental income of a 4-bedroom duplex in some suburbs of Sydney can mean up to $1400 in rent per week.

Minimise risk

Risks will decrease with dual occupancy because if there are two properties, the risk of both being vacant is low.

Reduce the cost of development

This can be achieved by selling one side of the dual occupancy.


Duplexes are a great way to start with and save money. If you can’t afford to buy a luxury home right away, duplexes are great to set you up financially to upgrade in the future.


With a duplex, you have the choice to either, rent or sell both sides, or live in one and rent or sell the other side.

Once you’ve determined council regulations, subdivisions of land and utilities, the other factors outlined in Part One of this blog [insert link], and have a contract with a Builder, and the building stages will begin.  Looking for dual occupancy? Look no further! MJS Construction Group has you covered. 

Most Commonly, The Key Stages Of The Building Will Be:

Stage One: Site Start

The very first thing your builder will do is ensure the land where your dual occupancy will be built has been cleared, with soil tests also carried out to help determine the types of materials to be used for your footing/s and slab/s.

Stage Two: Basics and Slab

This stage sees the basics installed for each home, including power and drains followed by the slab/s being poured.

Stage Three: Frame

Once the slab/s have been poured, your builder will have carpenters on site who will erect frames along with the roof trusses.

Stage Four: Lock-Up

This stage will see your build transform right in front of your eyes, leaving you with a home you can ‘lock-up’. This stage is a busy one and includes the addition of windows, gutters, bricks, roof covering and doors.

Stage Five: Fixings

The fixing stage is where your builder will have all internal fixings installed, including cupboards, basins, baths, flooring, plaster walls, ceilings and stairs.

Stage Six: Completion

As the last phase of the building process, your builder will now be finalising the little details that make your house a home. From painting and tiling to external rendering and garage doors, your home will be completed with all your chosen fittings and is almost ready to be moved into with your family and tenants if you are going down that route.

Stage Seven: Settlement

Your builder will send through a Certificate of Occupancy which you’ll need to forward to your loan provider. Once received, it will send a valuer to inspect your property to ensure it’s built to the highest standard and meets the requirements for the duplex or granny flat build. This certificate confirms that your new home is ready and that all work has been completed as per your contract.

Stage Eight: Move-In

This is the most exciting part of your home building journey. Once you’ve settled with your builder and your loan provider, it’s time to move in! If you’re renting out your granny flat or duplex, now is the time to find a property manager and advertise for tenants.

Dual Occupancy And Multi-generational Living

Evaluate your options

The first and biggest, decision you need to make is what kind of living style is going to work best to fit your lifestyle and goals not only now, but in the future.

Everyone’s situation and personal preferences are different. For example, is it mandatory to have two defined entrances and homes? 

If you’re looking for distinct living homes with separate entrances, no shared rooms, living spaces, then a duplex or detached granny flat are your choices. 

If not, you can add inter-generational house designs to the mix. This is a single dwelling designed for more than two generations of a family, for example.

  • A home with two separate living spaces (one area will be smaller). In this area of the home, you will find a single kitchen, bathroom and master bedroom all contained within the family home. It’s perfect for the extended family who wants to have their living and cooking space.
  • A home with two master bedrooms and ensuites on different floors to accommodate a family and grandparents. You share living and cooking areas, but you have the ability to have guests or grandparents stay downstairs with their bedroom and bathroom.

dual occupancy

Understand council requirements

Navigating the landscape of government and council requirements is much easier with the help of an experienced builder.

There are many parts of the process you will need to know. Does the local council permit dual occupancies under its Local Environmental Plan? Are there any exceptions? What is the minimum width for a block under NSW Government regulations? Do you have a strict maximum floor space ratio and building height? 

Every council has other individual levels of control over the block of land you want to build on.

For detached granny flats, you will need to know the setback requirements, minimum block size and zoning before you commit. Will council permit a double-storey granny flat?

Do you need to subdivide?

Knowing what you can do with your land is also important if you want to sell one of the dwellings in the future and keep the other. Councils will advise you if subdivision – Strata or Torrens – is permitted with the construction of your dual occupancy.

It is critical to have the right title on the land and know if you are able to subdivide. Preparing for this at the planning stage in consultation with your builder is the best time to do this. If the subdivision is permitted, it’s best to do this at the same time as the application for the construction of the dual occupancy. Planning for a new look for your house? Look no further!  MJS Construction Group is here to help in your dual occupancy builder Melbourne.

The differences are:

Torrens – this is the subdivision of one lot into two, and there are no shared services.

Strata – if your land cannot meet the requirements for a Torrens subdivision, you may be able to have a Strata title, similar to that of a townhouse or apartment building.

This means that you will need to work with the resident of the other unit for joint concerns (for example, maintaining a roof). When you subdivide, you will need a surveyor or conveyancer to change the details on the first title and to create a new title that will represent the now separate second property. Once you’re the official owner of two legal residences, you can sell one or both.

Note that a granny flat is different as it’s considered to be a second dwelling on one title and as such, can’t be sold separately to the main house.

Some rules govern different property types is slight afferent from state and local council. These can easily confuse one for what classifies as duplex and dual occupancy. The design of the home can be similar or different between the duplex or dual occupancy. It is sometimes legally permissible for a land title that usually counts on defining the property type. Suppose one is thinking of a building on a multi-dwelling property type on a single block of land. One should be assured to research the options that are available to them and as any browser would need more time and money to build a duplex, whereas, the dual occupancy house is more cost-effective but has limited options.

One should refer to dual occupancy builders in Melbourne to know more about such properties; LBD homes help one to shed light on this subject more precisely.

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