Secondary dwelling (granny flats)
Brisbane City Council developed Brisbane City Plan 2014 (City Plan) in consultation with the community, to support a simple, clear and streamlined development assessment process. The plan guides Brisbane's land use and development to support population growth.
City Plan encourages a variety of housing options to meet Brisbane residents’ diverse and changing needs. Under City Plan, Council defines a 'house' as a dwelling house. It refers to the residential use of premises for up to two dwellings, one of which is a secondary dwelling such as a granny flat. A dwelling house includes out buildings (e.g. carports or sheds) and works normally associated with a house, such as an extension.
This page outlines how City Plan applies a secondary dwelling in residential zones. It includes how to check planning approval and basic design requirements. A certifier must approve any work for a secondary dwelling before you start construction. This is separate to a planning approval.
Secondary dwelling approval requirements
City Plan refers to an extension to an existing dwelling house in a residential zone for a granny flat as a 'secondary dwelling'. The secondary dwelling can be a maximum of 80 square metres in size and must be located within 20 metres of the dwelling house code. No planning approval is required as long as you meet the accepted development criteria in the Dwelling house code or Dwelling house (small lot) code.
Standard lots are 450 square metres or greater in area, or for a rear lot greater than 600 square metres excluding the access way.
Small lots are less than 450 square metres, or for a rear lot less than 600 square metres, excluding the access way.
You will need to lodge a development application if:
- the secondary dwelling is bigger than 80 square metres in size; or
- it is more than 20 metres from the main house; or
- where not meeting all the relevant acceptable outcomes.
Zones, overlays and neighbourhood plans affecting a property
The City Plan online mapping tool allows you to view your property on a map. You can see the zones, overlays and neighbourhood plans that apply to your site.
If overlays or neighbourhood plans apply to your property, you will need to consider these in designing your granny flat. If your property is affected by biodiversity and wetlands overlays, your granny flat may require Council approval.
Setbacks from boundaries for secondary dwellings
The Queensland Development Code sets boundary setbacks for secondary dwellings on standard sized lots*. City Plan does not include boundary setbacks for a standard sized lot. The Dwelling house (small lot) code identifies boundary setbacks for granny flats on small lots**. Boundary setbacks help protect privacy and amenity and help with property maintenance.
* A standard sized lot is one that is greater than 450 square metres, or for a rear lot, greater than 600 square metres excluding the access way.
** Small lots are less than 450 square metres, or for a rear lot, less than 600 square meters excluding the access way.
Maximum site cover
'Site cover' is the proportion of the site covered by buildings. This includes the main house and secondary dwelling or any structure attached to the buildings and carports. It does not include structures such as gazebos or shade structures. For small lots, City Plan requires site cover of all relevant buildings and structures on the site to be a maximum of:
- 50% for lots 400 square metres or more
- 60% for lots 300 square metres or more and less than 400 square metres
- 70% for lots 200 square metres or more and less than 300 square metres
- 80% for lots less than 200 square metres.
The Queensland Development Code sets site cover restrictions for standard sized lots. These can be confirmed by a private building certifier.
Maximum height and storeys you can build without Council approval
9.5 metres and two storeys*
11.5 metres and three storeys**
* Rear and side wall heights cannot be higher than 7.5 metres. The maximum pitch to the highest part of the roof top cannot exceed 30 degrees on small lots.
** Rear and side wall heights cannot be higher than 9.5 metres. The maximum pitch to the highest part of the roof top cannot exceed 30 degrees on small lots.
Building up to the height specified in the table does not require development approval from Council if your development complies with all other requirements. However, you will need building approval from a qualified building certifier. If you are proposing to build higher, you will need to seek Council approval.
You must provide one car parking space on your site for a secondary dwelling and one car parking space for the main dwelling house.
Additional house numbers cannot be allocated to secondary dwellings or ‘granny flats’ as they are contained within the same land parcel (lot) as the main dwelling house.
Council allocates house numbers in accordance with Chapter 6 – Street Bridges and Culverts etc Local Law. Under the Local Law, only one house number can be allocated per registered lot on a plan of subdivision (identified by the Real Property Description).
This is to ensure the allocated house number clearly defines the area to which the numerical reference applies, and also provides a consistent identification method for properties across the city. These numerical references are used by emergency services and utility providers such as Australia Post and Energex.
Determine if an application is required
Council recommends you engage a building certifier or consultant town planner to confirm whether you need to lodge an application to construct your secondary dwelling. You can also phone Council on 07 3403 8888.
A certifier must also approve any building work for secondary dwelling before you start construction. This is separate to development approval. A building certifier checks that your proposed building work complies with the Building Act 1975 and associated standards.
Visit the Queensland Building and Construction Commission website for more information about building approvals and building certifiers.
For more information:
- register to receive email updates about City Plan and planning and development in Brisbane.
- attend one of the Talk to a Planner sessions that Council holds throughout the year to speak to a Council officer in person
- contact Council.
Disclaimer: The content on this page is a summary and has been prepared to assist the reader to understand City Plan. Please refer to the full City Plan document, entitled Brisbane City Plan 2014, via City Plan online for further detail.