Here is what you should know about investing in a granny flat and some of the ways it can add value to your property.

A granny flat – self-contained secondary accommodation within, attached to, or in the backyard of an existing property – can be a source of additional rental income and a way to add value to your property. We have been seeing that investors are achieving between 12 – 15% ROI.

But before you dive right in and start building an investment granny flat, there are a few things to consider.



The first thing you’ll need to do is check whether your local council allows you to build and rent out a granny flat on your property, and if they do, what rules and regulations you’ll need to comply with.

These differ from state to state. Some areas prohibit granny flats from being rented out, so you’ll need to be sure you’re up-to-date on the regulations for your particular area.

In NSW, the main rules for building a granny flat as a complying development are summarised as follows:

  • The secondary dwelling (granny flat) can be within, attached to or separate from the primary dwelling
  • There may only be one primary dwelling and one secondary dwelling per lot
  • The main property must be at least 450m² and within a residential zone
  • The granny flat’s floor area must not exceed 60m².

The full requirements for NSW granny flats can be found in the State Environmental Planning Policy.

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Privacy is a major concern when it comes to granny flats. The occupants of both the granny flat and the primary dwelling must have adequate privacy, and the granny flat should also have separate access.

Whether it’s from the side of the dwelling or from a laneway at the back of the property, your tenants should be able to access their flat from a completely separate entrance.

For these reasons, houses on corner blocks work best for granny flats, as the main property can face one street while the granny flat faces the other.

Depending on the type of granny flat you construct, other privacy measures that may need to be considered include:

  • Fences
  • Privacy screens
  • Trees or shrubbery

It’s recommended that your granny flat has its own separate connections to utilities such as water, electricity, gas, phone lines and the NBN. This is to ensure that your tenant can be charged separately and clearly for utilities and services.


Under a standard NSW residential tenancy agreement, tenants agree to pay for electricity, gas and water, provided the property is separately metered (and water efficiency measures are in place).

This is the same with tenanted granny flats, so be sure electricity and gas are separately metered, and that a sub-meter is installed for water.


Phone and internet connections should also be separate from those of the main residence.

Under the terms of the National Broadband Network, each service must be linked to a unique address, meaning that granny flats sharing the same address as the primary residence aren’t eligible for a separate NBN connection.

However, an additional service can be installed by a registered cabler to extend the existing service from the primary residence.


Unless specified otherwise in the tenancy agreement, the owner is responsible for the maintenance of common areas between the primary and secondary dwellings, such as gardens and lawns.

Key Takeaways


Before committing, it’s important to consider whether a granny flat actually has the potential to add capital value to your property, as well as providing rental income. In most cases, it will be provided it ties in well with the main property and has adequate privacy and separate access, as discussed above.

However, in some circumstances, the addition of a granny flat might actually devalue your property. If it takes up too much of the property’s outdoor space, lacks privacy (e.g. overlooks the main property), or is located in an area with an oversupply of granny flats, it might end up being the opposite of the value-add you’d hoped it would be.

It’s also worth keeping in mind that if your granny flat is built on the same lot as your principal place of residence, you may have to pay capital gains tax on the flat. This tax is based on how much space the granny flat takes up on the block of land, and is payable once five years have passed since construction.

If you are looking for more information on granny flat investments or, looking for general advice to start your property investment journey, get in touch with the Investment Services team today.

Contact us today[email protected]

Disclaimer: This information is general in nature and does not take into account your personal situation. You should consider whether the information is appropriate to your situation, and for professional advice, seek out a financial adviser.