Is It Cheaper To Build Or Buy A Duplex?

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Everyone loves a great deal, which is why home builders may be tempted by the idea of getting two homes for the price of one. Although it costs more to build a duplex than a single freestanding house, it’s usually cheaper than building two houses, and because both dwellings are on the same block, the land costs less than two separate lots.

Duplex projects have the potential for significant profits, but considering the hidden costs, determining whether a duplex is a good investment depends on several factors and diligent number crunching.

When embarking on the most significant and rewarding financial outlay of your life, saving money will always be the name of the housing game. So, if you truly want to wear a winner’s smile, a duplex is a proven way to keep those hard-earned dollars in your pocket. This is a 360-degree vision when launching into the property market. At MJS Construction Group, we have the best dual occupancy selection to make your house a dream come true.

What Is A Duplex, And Why Would You Want To Build One?

A duplex house is a type of residential property that has two separate dwellings under one roof, each with separate entrances and utility meters. Unlike a single-family home, a duplex allows for dual occupancy, meaning the landlord can increase income while minimising overhead and reducing risk. If one unit becomes vacant, the landlord still has one unit producing income and covering certain expenses such as property taxes, insurance, or financing costs.

The Evolution in Duplex Development

The Australian property industry has been changing in recent years, and so have been the trends in duplex development. In the past decades, duplex dwellings were not considered particularly cool and trendy. The duplex architecture was one that was ugly but functional, and they were primarily situated in dodgy suburbs, the kinds that buyers and renters hated to live in.

A few decades ago, buyers and tenants were not the demanding and discerning type like today’s sophisticated consumers. They had a completely different idea of good quality, and they weren’t too fussy about the location and the quality of the duplex architecture. Besides, many buyers preferred the large blocks of detached developments situated far away from the central business district. Duplex dwellings were not particularly popular with consumers two or three decades ago. They were hard to market, and the rental yields weren’t strong to justify the significant investment.

The change in tastes and perception began around 2014 due to the skyrocketing prices of land in the major Australian cities. The demand for housing shifted from large detached units to smaller duplex dwellings as many consumers were priced out of the detached units market. Suddenly, the duplex dwellings were in vogue, and duplex developments became some of the best industry performers as consumers shifted to smaller living spaces.

Today, a duplex dwelling is an aspiration for many an Aussie homebuyer. It is

It’s a good compromise midway between living in a highrise apartment and enjoying a quiet luxury lifestyle in Toorak. The duplex development concept is now famous, not just with buyers but also with many developers.

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Two Homes, One Block – The Financial Benefits Explained.

In it to win it

When setting your toes into the housing landscape, who doesn’t want to have their investment cake and eat it too, if handled shrewdly, a duplex offers one of the easiest and most lucrative entries real estate world. In the simplest of terms, a duplex – defined as two homes created on the same title – makes the most of your entire living space by following the fundamental idiom of a problem shared is a problem halved. In this way, a duplex doesn’t generate the complexities inherent in subdividing land. Instead, it processes both combined properties under the same roof – each boasting their own comfortable and individual living quarters, with all of the assets and necessities of everyday life. 

Long-term vision

On top of all those immediate advantages, duplex owners also benefit from higher tax depreciation on their investment. So not only are you making the most physically of the block size you’re building or remodelling on, you’re squeezing the maximum gain out of your financial outlay. In short, a duplex engages with the future potential offered by your land in ways traditional subdivided land can’t. It also strategically adds a significant upswing on the return from your investment.

That’s why duplex ownership is increasingly seen as a high-yield financial option. Owning a duplex translates in basic terms as retaining two individual homes on the one block, offering a dual-income potential across the single plot of increasingly valuable land. Because of this, one of the most significant financial advantages of holding a duplex is that you can also personally settle into one residence yourself while placing the other on the rental market.

This will, of course, bring in a steady income flow while halving maintenance fees and expectations. This then bounces the advantage of making your rental property far less stressful to manage, as it is right next door to you.

Things To Consider When Building A Duplex

There are several things to consider when it comes to duplex development. First and foremost is picking the right lot to develop. Zoning laws and the land cost are significant factors in whether the investor can create the property as hoped or intended.

  • Cost of construction for the area, including material cost and labour cost.
  • Timeline and process of getting building permits with the county or local municipality.
  • Current or planned development that could positively or negatively impact the duplex project.
  • Potential sale value and rental rates. You should know the potential income the duplex investment can produce or its value upon completion, which will justify the duplex construction cost and financing costs before building.
  • What design, square footage, and floor plan will appeal to buyers and tenants in that market.
  • Supply and demand in your local market. Is building justified, or is the market oversaturated?
  • What builder, architect, and engineer you will work with to complete the job.

Get a Financial Preapproval

Before you get started with your duplex development, the first step is to get a preapproval for your duplex financing. There are various lenders in Australia that can offer you well tailporedduplex development loans. Lenders offer different financial packages for dual occupancy developments, although they generally cap the loans for duplexes at about 80% of the property’s value. For low doc loans, they will even fund less of the value of the project. However, based on the value of your duplex investment property and the location, it is possible to get financial institutions willing to lend you more for the duplex development.

Get the Council Requirements for Dual Occupancies

Every local area has duplex town planning requirements that you will need to adhere to. Before you embark on the project, familiarise yourself with the local environmental plan and the local council’s development control plan. You need comprehensive information on the required lot area for duplex development in the local council and the kind of designs and duplex architecture that are permissible.

Ensure Proper Zoning

If you have met the council requirements for the dual occupancy development, you will need to focus your attention on the site where you want to develop your duplexes. Take measures to ensure that the site has been properly zoned for duplex development.

Work through the council zoning and planning regulations to ensure no covenants on the land may hinder the project’s smooth implementation. The key to success in surmounting zoning obstacles is to do thorough research about the location. Before you proceed with a duplex investment, make sure you understand the site and the council regulations well. At MJS Construction Group, we offer a wide range of duplex build.

Does The Land Meet The Dual Occupancy Criteria?

Assess the lots where you are planning to build and determine if they meet the dual occupancy criteria. An essential criterion is a size. Look at the frontage and see if it meets the minimum width requirements for your dual occupancy.

If you are planning to build a duplex development, you will need a minimum frontage ranging from 18m to 20m. The size of the frontage will ultimately depend on your unique duplex design.

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Check Your Planning Certificate.

Still, on the due diligence, give your building a second look to check whether the area you are planning to build the duplexes in is prone to bush fires or flash floods. While you can still build duplexes in a disaster-prone site, it is going to increase the cost of development.

Get Your Duplex Builder To Look At The Site.

Your site must have met all the compliance requirements set out by the local council, but it is advisable to have a professional builder look at the site. They can give it a fresh set of eyes and identify the challenges and opportunities that might not be too obvious to someone who is not an experienced builder.

Do A Feasibility Study On The Viability Of The Project.

To establish the viability of the project, it is advisable to do a feasibility study in order to get a bird’s eye view of the suitability of the project at that particular location. There are variables that you can factor in to establish whether the project will be the right fit. Look at the duplex market in the area. What are some of the recent comparable sales? You can base the end value of your duplex development on the current sales that have been witnessed in the local real estate market.

Acquire The Occupation Certificate

Upon the completion of the duplex property building work, apply for an occupation certificate for the development. Once this is issued, your duplex development can be tenanted or put on the market for sale. Upon completing the duplex property development, it is also advisable to order a depreciation schedule for the property. You can do this by simply emailing the building plans, tender and miscellaneous cost details to a professional quantity surveyor.

Apply For A Subdivision Certificate

Last on our duplex checklist is the application for the subdivision certificate. After the relevant council has issued this, you can register the subdivision once your lender has signed off on the development. However, if you plan to hold the duplex development for some time and are not planning to refinance the property, there is no hurry in rushing for a subdivision certificate. Besides, certain costs of holding the property, such as the rates, will be cheaper if you keep your duplex development in one title.

All Gain, No Pain

As you will only be paying the single council rates invoice, this minimises outgoing expenditure while maximising incoming profit.  Planning for a new look for your house? Look no further!  MJS Construction Group  is here to help in your dual occupancy builder Melbourne.

If, however, you choose to rent out both dwellings, as many savvy duplex owners do, this will result in double the income received from your single property. Then, if the time comes when you decide to sell your duplex and consolidate your vision towards a higher position in the housing game, you will be placing two unique dwellings on the market. Both of these will likely present as cheaper than a single total freehold housing option and therefore be more appealing to buyers seeking a more financially feasible purchase.

As a result, blocks of land featuring a duplex structure also generally achieve a comparatively higher resale value, as both residences come with their amenities such as a bathroom and kitchen.

To sum up, investing in a complete duplex can offer advantages such as doubling your income should you place both up for rent, as well as slashing your outgoings considerably. Or purchasing one unique residence in a duplex can halve the at-times seemingly prohibitive cost of entering the property market for newcomers. Where else can you find a win/win situation these days?


Hopefully, this duplex advice will help you put things together when planning to pursue duplex development. The duplex checklist doesn’t have to proceed in a logical sequence. Some of the steps you will have to pass through, especially regarding duplex town planning and development approvals, might not be straightforward. However, a lot of due diligence and professionalism are required as mistakes can prove quite costly during a duplex development.

Suppose you are not experienced in this area. In that case, it is generally advisable to use a professional and specialised duplex builder with the expertise and experience in navigating past many of these challenges and delivering flawless duplex development in time.

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