6 Things You Should Know Before Building a Granny Flat

  • Article by: Samara Amadi

A granny flat is a fantastic way to make use of your land and increase the living space of your property. Whether you want to rent the space out, provide a safe and nearby accommodation for elderly relatives (hence the name!), or simply want to provide more liveable space for your growing family, a granny flat is an affordable and reliable solution.

There’s also been a growing trend to generate some income by building a granny flat to use as bed and breakfasts thanks to the popularity of Airbnb.

Granny flats are perfect for many Australian suburbs and regional areas where backyards are plentiful. It was once commonplace for Aussie families to have big backyards however our needs have evolved over the years. In years gone by, many of us craved a big backyard to enjoy with family and friends. Now, the cost of land makes this no longer affordable for many Australians.

Once upon a time, we enjoyed a hit of backyard cricket with the family on Christmas day. We’ve changed as a society in many ways, so too our needs have changed. We tend to live in larger homes on smaller land. Many of us now live extremely busy lives so maintaining a big backyard is no longer viable. Subdividing is a popular option for many however it’s not practical or possible in some locations. Granny flats provide a popular alternative.

Granny flats are versatile additions to many properties however, there are a few things you should know beforehand; read on to find out more about planning and building a granny flat.


Get approval 

People often mistakenly believe that building a granny flat is like putting a small shed up in your garden, but unfortunately that is not the case. Because a granny flat is intended to be lived in and will require electricity, plumbing and possibly gas, you will need to apply to your local council for approval. Rules do vary from state to state and council to council. For example, in Victoria you’ll need to consider the Secondary Dwelling Code.

Some states have planning policies in place designed to encourage more affordable housing so granny flats are favourable by some councils, while other councils are trickier to deal with. If you are buying a house with an existing granny flat, it’s important to make sure the appropriate permits were granted. It’s also worthwhile having it professionally inspected particularly if it was constructed by an owner builder.


Size matters

There will be a maximum size your granny flat is allowed. For example, in Victoria it cannot exceed 60sqm although your local council may have even greater restrictions. If you want your granny flat to be approved quickly contact your local council to find out any specific requirements you may need to abide by. Technically you may be able to build larger than 60sqm however it may no longer be considered a granny flat. Anything above the limits will need more consideration and the planning permission process can take much longer.



It’s a common misconception that your granny flat has to be separate from the main building on your property to qualify. This isn’t necessarily the case however it usually makes better sense if space allows for it. Stand-alone granny flats can also be built quite closely to existing buildings when required.

By clever placement of your granny flat, you may be able to create two private spaces in your backyard. This will help residents of the granny flat and the main home both feel like they have their own space. With some clever design, you’ll create a beautiful private outdoor space, providing a sense of bringing the outdoors inside.


Make serious profit

Gateway Bank estimated that 23 per cent of granny flats are rented out on either a short-term or long-term basis. With sites like Airbnb making home stays more appealing, tourists are always on the lookout for affordable and comfortable accommodation. In many locations, the small investment of a granny flat can quickly be recouped and you can quickly profit off your investment.

 granny flat new build
Source: The Mangrove by TR Homes 

Structurally sound

The most common misconception about granny flats is they are low-quality ‘kit homes’ and can be constructed on the cheap. This simply isn’t the case. While there may be cheap options on the market there are certainly plenty of modular, pre-fabricated granny flat builders around Australia that we highly recommend. Granny flats should be treated with the same care and consideration that you would apply when building a new home.

Think long-term

If you want your investment to be safe and long lasting, you should use qualified professionals to build your granny flat to ensure it’s structurally sound. While you may be tempted to produce a DIY granny flat to save some money, you’ll probably end up spending more on maintenance and repairs than you would have spent on a professionally designed and constructed building. You’ll also find that the aesthetic of professionally built granny flats is much more appealing to renters and you’ll be able to earn more back on your investment.

Published: 16/11/2020
Author: Samara Amadi