The Australian Granny Flat, or secondary dwelling, is a self-contained living space located within, attached to, or separate from a main house on the same property.

Typically smaller than the main house, granny flats and secondary dwellings are often used as a form of affordable housing or as a way for older family members to live independently while still being close to family.

Granny flats in Australia are typically built to comply with local building codes and zoning regulations. They are usually equipped with independent facilities, such as a kitchen, bathroom, and living area, allowing the occupants to live independently without needing to access the main house.

Granny flats can provide a range of living arrangements while maintaining privacy for various situations, like hosting guests, living spaces for older children, housing multiple generations or serving as an additional source of income via rental fees. These benefits make dual occupancy building solutions a desirable and cost-effective option for investors and families. Granny flats are also a great choice to provide independent living for disabled relatives.

What is a Granny Flat?

Planning NSW defines a secondary dwelling, or granny flat, as “a self-contained dwelling located within, attached to, or separate from another dwelling on the same site.”

Moreover, “A lot on which a secondary dwelling is constructed cannot be subdivided. The development of a secondary dwelling can only result in there being one principal dwelling and one secondary dwelling on the site.” In short, you cannot build another dwelling on a duplex or a property with an existing secondary dwelling or granny flat.

History of the Australian Granny Flat

The history and context around the Australian granny flat can be traced back to the post-World War II period. Following the end of the war,  the government launched a housing initiative to provide affordable housing for returning veterans and their families. This program led to a significant increase in the construction of smaller, more affordable homes, many of which were granny flats.

As the population grew and the land became more scarce and expensive, granny flat builders became an increasingly popular option for homeowners who wanted to add a secondary dwelling to their property without purchasing a separate piece of land. They were also popular with older family members who wanted to live independently but still be close to family.

Over time, granny flat designs have become more than just a simple living space for older family members. They are now considered a viable option for affordable housing, and many local governments have relaxed regulations around the construction of granny flats to encourage their use.

In recent years, granny flats have become an essential part of the Australian housing market, as they provide an affordable housing option for people who cannot afford a standalone house. They are also increasingly used as short-term rental accommodation or to house family members or friends.

In summary, the history and context of the Australian granny flat are closely tied to the history of affordable housing in Australia. Granny flats in Australia have evolved to become a popular option for homeowners looking to add a secondary dwelling to their property and those looking for an affordable housing option.

Granny Flat Rules & Regulations

The Affordable Rental Housing State Environmental Planning Policy 2009, sometimes known as the “SEPP,” is the name of the current legislation that dictates whether you can build a granny flat or secondary dwelling on your property.

The size of your land is one of the primary requirements for secondary house development. Except when the secondary dwelling is contained within an existing dwelling house, you must have an area of at least 450 square metres. The size of your granny flat floor plans is also restricted to 60 square metres.

Other restrictions include:

• maintaining a height of 8.5 metres,
• a minimum courtyard space of 24 square metres,
• a 12-meter width at the building line of your current main house for the only secondary dwelling on the site
• Setbacks of three metres from the main house’s back
• 0.9 metres from its side boundaries,
• a distance of three metres from any existing trees with a height of more than six metres is required for pedestrian access distinct from the primary residence.

In accordance with State Environmental Planning Policy requirements, you must construct your primary residence before your secondary.

We strongly advise contacting your local council to learn more about the rules and regulations that apply to the construction and design of granny flats.

Attached & Detached Granny Flat Designs

Depending on the size of your property, the house’s design, and the additional building space available, you’ll need to decide between an attached or detached dwelling.

A granny flat is considered “attached” if it is physically connected to or integrated into the main house. To have an attached dwelling, you must build an additional living space next to your house or convert a portion of your current home into a living area.

An attached granny flat is better suited for residences with smaller lots or convenient access to the main house. However, detached dwellings are often more expensive because attached granny flats must share a single wall.

A detached secondary dwelling is a self-contained living space positioned separately from the main house on the same property. This granny flat is more independent from the main home, which can benefit renters or family members who prefer more privacy. Detached granny flat designs can also be more energy-efficient and potentially more sustainable than the original house.

Why You Should Build an Australian Granny Flat

Building a granny flat is advantageous for several reasons: a place for weekend visitors to stay, living with older relatives in a multigenerational home, or using live-in babysitters! While it comes at the cost of a smaller backyard, the extra room and flexibility for visitors will be worth the price, especially considering the possible return on investment (ROI).

Having a granny flat rental on your current property could bring in a respectable income with an ROI of between 10 and 20 per cent. Additionally, it will raise the value of your home by up to 30%!

In addition to providing affordable aged care, secondary residences can also help disabled family members live independently with funding from the NDIS and with the permission of an Aged Care Assessment Team for subsidised at-home care.

Build Your Granny Flat The Better Way

The typical or standard process for building a granny flat or secondary dwelling can vary depending on the location and the specific regulations in place. However, generally, the process can involve the following steps:

Research: look into local zoning regulations and building codes to ensure that the proposed granny flat floor plans and design comply.

Planning: Prepare a detailed outline of the proposed granny flat designs, including floor plans, elevations, and site plans.

Permits and approvals: Obtain the necessary licenses and permissions from the local council or building department, such as building, plumbing, and electrical permits.

Site preparation: Prepare the site for construction, including excavation, levelling, and connection to utilities.

Construction: Begin construction of the granny flat, working closely with the builder to ensure that all aspects of the project are completed according to plan.

Inspection: Schedule and pass all necessary inspections by the local council or building department, including building, plumbing, and electrical inspections.

Occupancy: Obtain an occupancy permit from the local council or building department, indicating that the granny flat is safe and suitable for occupancy.

It’s important to note that the process may vary depending on the jurisdiction, the complexity of the project, and the specific regulations in place. It may be necessary to consult with local authorities or professionals such as architects, engineers, or builders to ensure that the process is done per the local laws and regulations. It’s also important to consider the time frame for the whole process, as it may take several months from the initial planning to the final occupancy.

Ready to start building your Australian granny flat? Consider dual occupancy house plans that already include a granny flat to avoid modifying your dream home plan.