We build more duplex homes than any other type of home at ZAC Homes and with 20 years in the industry, we’ve built literally thousands of duplex homes for families and investors.

Here are the most frequently asked questions we’ve compiled from our many years of building.

What is a duplex?

The terms ‘duplex’ and ‘dual occupancy’ are often used interchangeably, but there is one key difference. A duplex contains two dwellings under one main roof and can be built on a single piece of land or a subdivided block.

The benefit of a duplex on a subdivided block comes in when you want to sell one or both dwellings. However, a duplex is also still technically a dual occupancy home because it can be two dwellings on one block. Because of this, confusion over the two terms can still creep in.

In the Sydney building market, the term ‘duplex’ is generally used to describe two homes of similar size with a common wall, like ZAC Homes’ popular Gemini Designs. Our range of duplexes has been developed over the more than 20 years that we’ve been building duplexes.

What are the advantages of building a duplex?

The biggest advantage is that you can build two homes on one suburban block of land.

You can take an older rundown house on a block of land, then turn it into a knock down rebuild project and end up with two brand new homes.

Building a duplex is an excellent way of maximising the value of your land by building one home to live in and another to rent or sell. A duplex is also a great way for a multi-generation family to live together but have separate homes.

In terms of costs, it is also a very economical way to build two homes. If you were to build two dwellings on one block of land the costs would be significantly higher.

Are there any differences between building a single dwelling or a duplex?

When it comes to building a duplex, rather than a single dwelling there are a few differences.

You must have a Hydraulic Plan which shows how rainwater will be drained from your land and where it will go. You must also have a Landscape Plan which takes into consideration your local council’s requirements as well as the Hydraulic Plan.

On the upside, you have the potential for subdivision. In some but not all cases, your council may allow you to subdivide which will enable you to sell each home as an individual property.

How much land do you need to build a duplex?

Under the NSW Low Rise Housing Diversity Code, blocks must be either 400 square metres or the minimum lot size required by your council, whichever is greater. Blocks must be a minimum of 12 metres wide and buildings must have a minimum side setback of 0.9 metres.

Additionally, each dwelling must be 5 metres in width and a maximum height of 8.5 metres and must face a public road. Blocks where the duplexes have dwellings placed one above the other must be at least 15 metres in width.

Do I need to subdivide to build a duplex?

No, it is possible to build a duplex and not subdivide the land. However, you will not be able to sell the two homes separately if they are not subdivided because they will be on one land title.

This might be your preferred option if you plan to keep both homes after you build your duplex and have family members live alongside you.

Can I build a duplex on a corner block?

Yes, a corner block can be an ideal location for a duplex if the block meets requirements from your local council and government regulations.

At ZAC Homes we have standard designs that can be modified, or we can work with you on a custom design.

One thing you need to consider with any corner block build is the façade on both street views.

How much does it cost to build a duplex in Sydney?

Many variables go into the cost of building a home including the land, the size, the materials, fittings and fixtures chosen, the quality, the custom design, and more.

While building a duplex can be more expensive than a single or double storey home, it is still cheaper than building two separate homes because of the economies of scale with a common wall. For investors, the cost can also be offset by the potential rental or sales returns of two properties.

Speak to our experienced team today to get a better understanding of the costs involved in building a duplex on your property.

Are there duplex designs for narrow blocks?

Yes, the minimum width block you can build a duplex design home on is 12 metres wide.

With ZAC Homes standard designs including the Arabella 25 and the Gemini 25/19, our minimum is currently around 13 metres wide but we can work with you on a custom design to fit the 12 metre minimum.

What approvals are required to build a duplex in NSW?

The Low Rise Housing Diversity Code applies to all local government areas in NSW and allows dual occupancies to be approved through the fast-tracked Complying Development process. The new code applies to properties zoned R1, R2, R3 and RU5 across NSW, with designs also required to meet the Low Rise Housing Diversity Design Guide.

Using a private certifier and the Complying Development process means the planning and construction for your duplex approval avoids the need to go through your local council.

Build a duplex with ZAC Homes

Building a duplex home can be financially beneficial, and a great option for your family home, if you choose the right builder.

Custom-built dual occupancy homes by ZAC Homes are designed to optimise your available space and make the most of your valuable land. We pride ourselves on our exceptional customer service and make the journey of building your new home as easy and rewarding as possible.

ZAC Homes builds with trust, respect, integrity and pride, which we work hard to deliver to every client. Call us on 1300 350 793 or send us an online enquiry and our team will work with you to design and build your dream home.