In Queensland, the regulations surrounding granny flats (legally termed secondary dwellings) changed significantly on 26 September 2022. Previously, most councils only allowed family members to live in these units, but state-wide amendments now permit homeowners to rent them to anyone.
While renting is now easier, building a granny flat still requires strict adherence to local council planning and building standards.
Key Features of QLD Granny Flats
- Maximum Size: Usually capped between 80m² and 90m² depending on the council.
- Subordination: Must be used in conjunction with and remain secondary to the main house; it cannot be subdivided or sold separately.
- Facilities: Must include a kitchen, laundry, bathroom, and toilet.
- Parking: Most councils require at least one dedicated off-street parking space for the secondary dwelling.
- Separation: A minimum of 1.8 metres fire separation is typically required from the primary dwelling.
Council Approval: When is it Required?
In Queensland, you always need building approval, but you may not always need a separate Development Application (DA).
1. Building Approval (Mandatory)
Every new secondary dwelling requires building approval from a licensed private building certifier. This confirms the structure meets the National Construction Code (NCC) for safety, fire protection, and energy efficiency.
2. Council (Development) Approval (Conditional)
A full DA is often unnecessary if your project is classified as “accepted development”. However, you will likely need council approval if:
- The flat exceeds the size limit (e.g., larger than 80m² in Brisbane).
- It is located more than 20 metres from the main house.
- The property has specific overlays (flood, bushfire, character, or biodiversity).
- Your lot is smaller than the minimum size required by the local planning scheme (often 450m² or 600m²).
Site Preparation Considerations
Preparing the land correctly is vital to avoid cost blowouts later.
- Surveying & Soil Tests: Essential to determine the “reactivity” of the soil, which influences foundation depth.
- Utility Connections: Granny flats usually share the main house’s water and sewer connections, but separate sub-metering for electricity is recommended if renting.
- Build Over Asset (BOA): If you are building within 3 metres of a council sewer or water pipe, you must get approval from the asset owner (e.g., Urban Utilities).
- Flood Management: If in a flood overlay, the floor level must often be at least 300mm above the nominated flood height.
Range of Costs (2026 Estimates)
Building costs have risen due to material and labour demand. Below are typical “turnkey” price ranges for Queensland.
| Dwelling Type | Size (Approx.) | Estimated Cost (AUD) |
| Basic Studio/Cabin | 30m² – 45m² | $70,000 – $150,000 |
| 1 Bedroom Flat | 45m² – 60m² | $150,000 – $220,000 |
| 2 Bedroom Flat | 60m² – 80m² | $180,000 – $300,000 |
| Premium/Custom | 80m²+ | $300,000 – $380,000+ |
Note: Kit home prices often exclude assembly, labour, and service connections, which can add $80,000+ to the final bill.
Where are Granny Flats Not Allowed?
You generally cannot build a secondary dwelling if:
- No Primary House: A secondary dwelling cannot exist on a vacant lot by itself.
- Site Coverage Limits: Most councils restrict total building coverage to 50% of the lot. If your main house and shed already cover this, a flat may be rejected.
- Environmental Zones: Certain high-risk wetlands or environmentally protected areas may prohibit additional dwellings.
- Zoning Restrictions: Some specific rural or conservation zones have stricter limits on density.
Frequently Asked Questions (FAQs)
1. Can I rent my granny flat to someone I don’t know?
Yes. Since late 2022, Queensland state law allows you to rent secondary dwellings to anyone. You should use a standard Residential Tenancies Authority (RTA) agreement.
2. Does a granny flat need its own council rates?
Generally, no. In most QLD councils, a secondary dwelling is viewed as an extension of the main house and shares the same rates and bins. However, some councils may apply an infrastructure charge if the flat is very large.
3. Can I subdivide the land and sell the granny flat later?
No. Legally, a secondary dwelling Granny Flat is subordinate to the main house. If you want two saleable properties, you must apply for a Dual Occupancy, which is a much more complex and expensive planning process.
4. How far from the fence does the flat need to be?
Standard setbacks are typically 1.5 metres from side and rear boundaries, but this varies based on building height and lot size.
5. What are the fire safety requirements for renting?
If you rent out the granny flat, it must have hard-wired, interconnected photoelectric smoke alarms. If the flat is attached to the main house, specific fire-rated walls and sound insulation may also be required.
