Dual living - secondary dwelling

'Secondary dwelling' is defined by the Planning Regulation 2017 as follows:

Secondary dwelling means a dwelling on a lot that is used in conjunction with, but subordinate to, another dwelling on the lot, whether or not the dwelling is:

(a) attached to the other dwelling or

(b) occupied by individuals who are related to, or associated with, the household of the other dwelling.

To help with interpretation of the above definition, an understanding of other, related definitions within Schedule 24 of the Planning Regulation 2017 (current as at 11/2/2026) is needed.  These definitions include:

Overall, a secondary dwelling is an extension of a dwelling house use (whether attached or detached to the primary dwelling). 

Generally a secondary dwelling is smaller in size and scale, commonly known as a granny flat.  A secondary dwelling cannot be developed by itself as it always accompanies a main dwelling.

A dwelling (including a secondary dwelling) is rated the same as standard dwelling, sharing the same bins and connections such as electricity, water and sewer (where applicable). 

In September 2022, the State Government changed the definition of ‘secondary dwelling’.  Prior to these changes coming into effect, a dwelling house could include a secondary dwelling, however the occupants of the primary dwelling and the secondary dwelling had to be part of single household that comprised individuals who intended to live together on a long-term basis and who made common provision for food and other essentials for living.  To meet this definition, secondary dwellings were generally occupied by parents or adult children of the occupants of the primary dwelling house (commonly referred to as a granny flat or teenager retreat). 

With the State Government’s change to the definition, the occupants of a secondary dwelling no longer need to be related to or associated with the household of the primary dwelling. Therefore secondary dwellings can be rented out to anyone.

More information about the changes made by the State Government can be found here:

Changes to secondary dwellings | Planning

The definition change has helped to increase the availability and diversity of housing options which is a positive outcome in the current housing market.  However, it is important to recognise and understand that a dwelling house with a secondary dwelling is different to a dual occupancy.

Additionally, if you have a secondary dwelling that was approved in 2022 or earlier, you will need to check if any conditions on your approval restrict it from being rented out.  This was a common condition that was included on past secondary dwelling approvals, to ensure the development complied with the definition at the time.  If your approval includes a condition like this, you will need to apply to Council to have the condition removed (a change application under the Planning Act 2016) before renting out your secondary dwelling.

Yes.  All buildings used as a secondary dwelling will require building and plumbing approval. 

If you require further information on the building approval process or to contact a certifier please refer to Council’s website. https://www.redland.qld.gov.au/info/20198/what_approvals_do_i_need/984/private_building_certifier

Note that buildings used as a secondary dwelling will need to meet the standards of the relevant, habitable building classification.  To use an existing class 10a structure or the like (for example, a shed) as a secondary dwelling, the building would need to be changed to be able to be classified as a class 1 structure.  This may not be possible and it is recommended you contact a private building certifier to discuss this process.

Prior to the State Government changing the definition of secondary dwelling, Redland City Council did not include assessment provisions specifically relating to secondary dwellings.  This is because the definition alone sufficiently regulated secondary dwelling developments.  Following the definition change, Council increasingly became aware of examples of secondary dwellings being established in back and front yards that resembled dual occupancies in their size and operation.  As a result, a decision was made to introduce assessment provisions relating to secondary dwellings.

Currently, these assessment provisions are within Council’s Amenity and Aesthetics Policy and Guideline, however, they are intended to be incorporated into City Plan as part of a current, proposed planning scheme amendment.  The new provisions help to guide the development of a secondary dwelling to ensure it remains subordinate to the primary dwelling house on the lot.  The new provisions relate to the maximum gross floor area of the secondary dwelling and compliance with the Queensland Development Code (QDC).  It is noted that these provisions are similar to those already in other South-East Queensland local government planning schemes.

From a planning perspective, whether a planning approval is needed will depend on the individual aspects of a site, for example, zoning and overlays. You can view property details on development.i that provides you with a property report detailing the zone and overlays applicable to a site.  Further, redemap is the mapping which will show the extent of the zone/ overlays and other related information such as assets (water/ sewer/ stormwater), contours and easements. This information is available via Planning, building and development | Redland City Council.   

Where no planning approval is needed under City Plan, a referral to Council may be required as part of the building approval process.  This means that prior to a building approval being granted by a building certifier, a referral agency application may need to be submitted to Council to review of the proposal in relation to the amenity and aesthetics guideline.  This is required where the proposed development does not comply with the following probable solutions of Item 4 of the guideline:

Should you propose a secondary dwelling that does not comply with the above probable solutions, the referral will need to be approved by Council prior to building approval being granted.  Where a proposed secondary dwelling exceeds the gross floor area figures nominated above, you will need to demonstrate how the secondary dwelling achieves the following specific outcome:

Secondary dwellings are subordinate in size and function and ancillary in appearance to the principal dwelling house on the same lot.

Where a referral agency assessment for a secondary dwelling is required under Schedule 9, Part 3, Division 2, Table 1 (particular class 1 and 10 buildings and structures involving possible amenity and aesthetic impacts), the local government adopted charge for a ‘dwelling house’ will be levied for the secondary dwelling as a result of non-compliance with Item 4, probable solution P1 of the amenity and aesthetics guideline. 

In such circumstances the charge will be levied following the issue of a development approval (for material change or use or building works.) The relevant charge will be as follows:

• Where the gross floor area of the secondary dwelling is 85m² or greater and up to and including 112m² – 30% of the dwelling house charge; or
• Where the gross floor area of the secondary dwelling is greater than 112m² - 50% of the dwelling house charge; or
• Where in the rural zone and the lot size is 6,000m² or more and the gross floor area of the secondary dwelling is 160m² or greater – 30% of the dwelling house charge.

Infrastructure charges | Redland City Council 

Gross floor area (GFA), for a building, is defined by the Planning Regulation 2017 (current as at 13 Feb 2026) as:

- means the total floor area of all storeys of the building, measured from the outside of the external walls and the centre of any common walls of the building, other than areas used for—

(a) building services, plant or equipment; or

(b) access between levels; or

(c) a ground floor public lobby; or

(d) a mall; or

(e) parking, loading or manoeuvring vehicles; or

(f) unenclosed private balconies, whether roofed or not

Therefore, for a secondary dwelling, the GFA does not include vehicle parking areas (for example, garages and carports) or unenclosed balconies/decks/patios.

Currently, a dwelling (including a secondary dwelling) is rated the same as standard dwelling, sharing the same bins and connections such as electricity, water and sewer (where applicable).