The rules for secondary dwellings in Australia change so much between states and councils that what works in one suburb can be completely different just a few streets away. In Victoria, a 60 square metre granny flat no longer needs a planning permit in most cases, provided there are no flood, heritage, or bushfire overlays. In Queensland, the same size dwelling might need a full development application in one council area but be accepted development in another. This patchwork of rules catches a lot of homeowners off guard, especially when they discover the approval process after they’ve already chosen a design.
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This article is general information only and does not constitute professional advice. For your specific situation, consult a qualified professional.
Secondary dwellings — often called granny flats, studios, or small second homes — are a practical way to add living space or rental income to your property. But the approval process depends on where you live, what zone your property is in, and how big you want to build. Understanding those variables before you start designing saves time, money, and frustration. Here’s what you actually need to know.
A secondary dwelling is a self-contained home on the same lot as an existing primary dwelling. It has its own kitchen, bathroom, and toilet, but it cannot be subdivided or sold separately. The term covers granny flats, studios, and small second homes. The key difference from a dual occupancy is that a secondary dwelling is subordinate in size and function to the main house.
What I tend to notice is that people assume the rules are the same everywhere. They are not. The first thing to do is find your council’s specific requirements, because that single step determines everything that follows. For a deeper look at how council regulations shape property decisions, read our guide on navigating Aussie council regulations.
Council Size Limits Across Queensland
Queensland has no single statewide size limit for secondary dwellings. Each council decides its own maximum, and those numbers vary significantly. The table below shows the key differences between major Queensland councils. Victoria’s approach is simpler — a flat 60m² threshold for no planning permit in most residential and rural zones — but the same principle applies: your local council’s rules are the ones that matter.
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| Council | Max Size (Residential) | Max Size (Rural) | Distance from Primary | Key Rule |
|---|---|---|---|---|
| Brisbane | 80m² | 100m² | 20m | Accepted development if ≤80m² |
| Moreton Bay | 45–55m² | 100m² | 10m (res), 50m (rural) | Depends on lot size |
| Gold Coast | 80m² | 90m² | — | 50% site cover cap |
| Logan | 70m² | 100m² | 20m | Min 450m² lot, 15m frontage |
| Sunshine Coast | 60m² | 90m² | 20m | Similar external appearance |
| Ipswich | 50m² | — | 20m | 1 bedroom maximum |
| Noosa | 65m² | 65m² | — | 2 bedrooms maximum |
The numbers tell a clear story. A 75m² granny flat that sails through Brisbane’s approval process would be too big for Moreton Bay, Sunshine Coast, Ipswich, and Noosa. It would also require a planning permit in Victoria because it exceeds the 60m² threshold. The cost of getting that wrong is not just a rejected application — it’s redesign fees, council resubmission costs, and delays that can stretch months.
Other costs add up fast. A building permit in Victoria requires compliance with the 7-star NatHERS energy rating (from May 2024) and the Livable Housing Design Standard, which mandates step-free entry, wider doorways, and reinforced bathroom walls. Those requirements affect construction cost. If you need clarity on how property law intersects with your specific situation, a service like JustAnswer Real Estate Law can connect you with a professional who covers zoning and property transactions.
Common Mistakes With Secondary Dwelling Approvals
Assuming One Rule Fits All States
The biggest error is treating secondary dwelling rules as uniform across Australia. Victoria’s 60m² no-permit rule applies only in that state. In Queensland, the same size dwelling might need a development application depending on the council. The scenario: a homeowner in Moreton Bay designs a 60m² granny flat expecting it to be accepted development, only to discover the local limit is 45m² on their lot size. That means a full application, higher fees, and a longer timeline. The fix is simple: check your council’s planning scheme before you commission any drawings.
Forgetting a Building Permit Is Always Required
A planning permit exemption does not remove the need for a building permit. This catches people who assume “no planning permit” means “no approval at all.” In Victoria, a building permit is mandatory for every small second home, covering siting, design, safety, and energy compliance. The same applies in Queensland. Without a building permit, the dwelling is technically unlawful, which affects insurance, rental registration, and eventual sale. The process: submit construction drawings, engineering certificates, and energy reports to a private building surveyor or council. Allow 2–4 weeks for assessment.
Ignoring Property Overlays
Even in areas where planning permits are generally not required, overlays can trigger a full assessment. Bushfire, heritage, flood, and environmental overlays each have their own rules. In Victoria, a property in a bushfire-prone area means the small second home must meet specific construction standards, and a planning permit may still be needed. The percentage of properties affected varies by region, but it is common enough that skipping this check is a real risk. Use your state’s planning maps tool — the Victorian Government’s online tool is free — to identify overlays before you start.
Thinking You Can Subdivide and Sell
Secondary dwellings cannot be subdivided or sold separately from the main home. This is a hard rule in both Victoria and Queensland. Some buyers assume that building a granny flat today means they can sell it off as a separate lot later. Not true. The dwelling must remain on the same title as the primary dwelling. If you want two separate titles, you need a dual occupancy or subdivision approval, which is a completely different process with its own costs and conditions.
How to Get Your Secondary Dwelling Approved
Check Your Zoning and Overlays First
This is the step that determines everything else. Use your state’s online planning maps or your local council’s website to find your property’s zone and any overlays. In Victoria, the planning guide for one dwelling on a lot explains what’s allowed. In Queensland, each council publishes its own planning scheme. If you’re in a residential zone and there are no overlays, you are likely on the simpler path. If overlays exist, factor in the extra time and cost for a planning permit application.
Design to the Size Limit
Once you know the maximum size, design to stay under it. In Victoria, that means 60m² gross floor area. In Brisbane, 80m². In Ipswich, 50m². The gross floor area includes everything inside the external walls, so a few extra centimetres of wall thickness can push you over. Measure carefully. If you go over the limit, the entire approval pathway changes — from accepted development to a full planning application, which costs more and takes longer. A good draftsperson or building designer with local experience is worth the fee here.
Get Your Building Permit
This is the mandatory step everywhere. The building permit application requires: detailed construction drawings, structural engineering certificates, energy efficiency reports (7-star NatHERS in Victoria), and compliance with the Livable Housing Design Standard. In Victoria, the dwelling must also not be connected to reticulated natural gas — portable LPG is allowed. Submit to a private building surveyor or your council. Assessment takes 2–4 weeks. Once approved, you can start construction. The building surveyor will inspect at key stages: slab, framing, waterproofing, and final completion.
Meet Energy and Accessibility Standards
New secondary dwellings in Victoria must achieve a 7-star NatHERS energy rating plus Whole-of-Home energy requirements, which cover heating, cooling, hot water, and lighting. The Livable Housing Design Standard (from the 2022 National Construction Code) requires step-free entry, wider doorways and corridors, an accessible toilet on the entry level, and reinforced bathroom walls for future grab rails. These standards affect design and cost, so factor them in from the start. Retrofitting compliance after construction is expensive and sometimes impossible.
Do I need a planning permit for a secondary dwelling in Victoria? ▾
Can I rent out my granny flat to someone who isn’t family? ▾
What happens if my property is on a lot under 300m² in Victoria? ▾
Can I build a secondary dwelling on a rural property in Queensland? ▾
What is the difference between a secondary dwelling and a dual occupancy? ▾
Why the Rules Are Only Getting Tighter
Secondary dwellings are becoming more popular as housing affordability pushes people toward alternative living arrangements. But the regulatory trend is toward higher standards, not fewer rules. Victoria’s 7-star energy rating, the Livable Housing Design Standard, and the ban on reticulated gas all took effect in the last two years. Queensland councils are regularly updating their planning schemes, with Redland City Council currently progressing a major amendment. The direction is clear: build now to the highest standard, because the baseline is only going up.
Remember: this article is general information only. For advice on your specific situation, speak to a qualified professional.
If this was useful, you might also want to read essential due diligence for Australian land buyers.
Sources and Further Reading
Master the maze: navigating Aussie council regulations — A practical guide to understanding how council rules shape property decisions across Australia.
Victorian Government (2023). Small second dwellings planning and building framework. 🔗
Queensland Government (2022). Changes to secondary dwellings. 🔗
Cooe Architecture (2026). Victoria’s new granny flat rules. 🔗
