If you’re thinking about building a granny flat on your property in Queensland, you’re not alone. More homeowners are turning to granny flats as a practical solution for accommodating family members, earning rental income, or adding flexible living space to their backyard.
At Hoek Modular Homes, we know that navigating council rules and regulations can feel confusing, especially when it comes to secondary dwellings like granny flats. That’s why we’ve created this guide to walk you through everything you need to know about the Brisbane City Plan and what it means for your project in 2018.
Whether you’re designing a home for your parents, your young adult children, or even for tenants, understanding the current requirements can save you time, money, and stress.
A granny flat, also called a secondary dwelling, is a self-contained living space located on the same lot as your primary residence. It usually includes its own entrance, kitchen, bathroom, and bedrooms, and is fully detached or attached to the main house.
Granny flats are a great way to provide independent living arrangements for family members while staying close to home. They’re also becoming increasingly popular as a smart investment strategy, offering homeowners the chance to add rental value to their property or prepare for multigenerational living. However, before you begin building, it’s important to understand what the Brisbane City Plan allows—and when council approval is required.
In many cases, you might not need to lodge a formal application with the Brisbane City Council, depending on who is going to live in the granny flat and how the design fits within planning regulations.
If the granny flat will be occupied by members of your immediate household—for example, a parent, child, or another relative—it may fall under what’s known as “self-assessable” development. This means that you can go ahead with building without a formal application, as long as your plans meet the necessary criteria. These criteria are detailed in the Brisbane City Plan and help determine what’s considered low-risk development.
The City Plan defines a household as a single person or a group of related individuals who live together in a single dwelling. It also extends to situations like two adults caring for up to five unrelated children or a group of up to five unrelated people living together. If your proposed granny flat falls under one of these household categories, you’re generally in the clear to proceed without council approval. Still, we always recommend double-checking with a building certifier or planning consultant to be safe.
One of the first things you’ll need to look at when planning a granny flat is the size of your property. Brisbane’s City Plan has specific rules around lot sizes and how much of the site can be covered by buildings.
If your home is on a standard lot, the land must be at least 450 square metres in total to be eligible for a secondary dwelling without an application. For rear lots, which are lots that sit behind another property and are accessed via a narrow driveway or access handle, the minimum lot size is 600 square metres (excluding the access strip). If your property is smaller than these dimensions, it’s likely that you’ll need council approval before proceeding.
It’s also important to understand site cover, which refers to the percentage of your land that is covered by buildings. This includes your main house, the granny flat, sheds, garages, and decks. Site cover limits are designed to preserve green space, allow for proper drainage, and ensure privacy between neighbours. Depending on your lot size, these are the limits:
Going beyond these limits will typically require you to apply for council approval.
In some areas, you may find that your property is affected by specific neighbourhood plans or environmental overlays, which can influence what and where you’re allowed to build.
For example, lots that fall under a biodiversity or wetlands overlay may require special consideration and approvals to ensure your build doesn’t impact protected land or habitats.
You can check whether your property is subject to these conditions by using the Brisbane City Council’s online mapping tools. It’s a simple step that can save you from potential delays or rejections down the line.
No matter who you’re building for or where you’re located, there are some base-level requirements that apply to all granny flats across Brisbane.
One of the most important is parking. Your property will need to have an additional off-street car parking space for the granny flat, in addition to what is already available for the main house. This helps to reduce congestion and ensures that both households can come and go safely and conveniently.
Your granny flat will also need to have a private, separate entry. While it’s on the same lot as your main home, the idea is to ensure that each dwelling can function independently and privately, especially when it’s being rented or used by adults outside your immediate family.
If you’re planning to rent out your granny flat to someone who isn’t part of your immediate household, you’ll need to lodge a development application with the Brisbane City Council. That’s because you’re changing the intended use of the secondary dwelling from residential support to a commercial rental opportunity.
Once your application is approved, you’ll be able to advertise the granny flat as a separate rental property, giving you a legal and compliant way to earn extra income from your land.
At Hoek Modular Homes, we often help our clients through this process. We take care of the paperwork, liaise with council, and ensure everything is compliant, so you can focus on getting your property ready for tenants or family.
Even if you don’t need council approval, there are still certain building standards your granny flat must meet. These include restrictions on building height, number of storeys, and the slope of your roof—particularly for smaller lots.
For two-storey granny flats (up to 9.5 metres high), the side and rear walls should not exceed 7.5 metres, and the top of the roof should not have a pitch greater than 30 degrees.
For larger, three-storey dwellings (up to 11.5 metres), the wall height can extend up to 9.5 metres, but the same 30-degree roof pitch applies. These homes also need to be located in zones designated for low to medium density residential living or within emerging community zones.
If your planned design goes beyond any of these dimensions, you’ll need to lodge a formal development application. In many cases, it’s possible to get approval, especially if the design contributes positively to the area and follows general safety and amenity guidelines.
At Hoek Modular Homes, we understand that the technical side of building can be overwhelming. That’s why we manage the council approvals, building permits, and planning requirements on your behalf. From the very first enquiry, we’ll walk you through the process and provide you with a detailed information pack that outlines your role, our responsibilities, and the steps required to bring your granny flat to life.
You’re also welcome to tour our facility, meet our team, and even visit your home during the construction process. We’ll keep you updated with progress photos and provide you with a photo album so you can look back on how your home came together.
We pride ourselves on delivering more than just homes—we provide peace of mind and a smooth, enjoyable building experience.
While we’re known for our one and two-bedroom granny flat designs, we also offer a full range of modular homes—from compact studios to large, multi-bedroom homes for growing families. If you need more space, we offer custom modular designs with 3, 4, and even 5 bedrooms, tailored to suit your land, lifestyle, and budget.
No matter your needs, our team will work closely with you to create a home that’s practical, stylish, and built to last.
If you’re ready to build a granny flat, we’re here to help make the process easy and stress-free. Whether you need help understanding council regulations or want to explore your design options, the team at Hoek Modular Homes is only a phone call away.
Call us on (07) 3889 7385 or contact us online to request your free information pack and speak with one of our friendly modular home experts.
Your dream granny flat starts with expert advice, a trusted builder, and a home designed to fit your life. Let’s build it together.
