The number of Queensland homeowners adding a granny flat to their property has grown steadily, and the reasons are practical: rental income, ageing parents, adult children who need somewhere to live. What has not grown at the same pace is awareness of the rules. The most expensive mistake in this process is getting plans drawn before knowing what the block actually allows.

This article covers what Queensland calls these structures, what the size and setback rules look like across the Gold Coast and Brisbane, when you need council approval, and what the process looks like from the point of calling us to having approved plans in hand.

Secondary Dwelling or Auxiliary Unit: What Is the Difference?

Queensland planning law uses two classifications for what most people call a granny flat, and the classification determines what rules apply.

A secondary dwelling is a self-contained residence on the same lot as the main house. It has its own kitchen, bathroom, and living areas. It is designed for independent living, which means it can be rented out on the open market.

An auxiliary unit is a smaller dwelling that is functionally attached or connected to the main house. It is designed for a household member, typically a family member, rather than independent tenants. The occupation conditions for auxiliary units are more restricted than for secondary dwellings.

The distinction matters because they sit in different parts of the planning scheme. Before we draw anything, we confirm which category applies to your situation, because the drawings need to reflect the correct classification.

Size and Setback Rules: Gold Coast and Brisbane

The rules on size and setbacks for granny flats in Queensland vary between council areas and depend on the zoning and lot size of the property.

Both Gold Coast and Brisbane councils link the allowable size of a secondary dwelling to the size of the lot. Larger blocks generally allow larger secondary dwellings. If the lot is small, the size of the granny flat may be constrained beyond any statewide maximum.

Setback requirements apply from the front boundary, side boundaries, and rear boundary, and in some configurations, from the main dwelling as well. Heritage overlays, flood overlays, and vegetation overlays can all affect what is permissible in a given location. Checking the applicable overlays for the specific property address is part of our standard process before we quote.

On the Gold Coast, the coastal management overlay affects properties in certain beachside zones and adds requirements beyond the base planning scheme. In Brisbane, bushfire and flood overlays affect significant portions of the outer suburbs and need to be checked early in any planning process.

When You Need Council Approval

A granny flat almost always requires a development approval before construction begins. The approval process involves producing a set of plans that demonstrates compliance with the applicable codes, submitting those plans to the council or a private certifier, and receiving an approval notice before work starts. The drawings are not just a record of what you plan to build. They are the document the council uses to assess whether the structure complies with everything that applies to your specific lot.

What triggers a development application rather than a faster code-assessable pathway depends on the zone, the overlay conditions, and whether the proposed structure falls within the complying development thresholds. We assess which pathway applies as part of the initial scoping process.

What We Produce and What the Process Looks Like

When you contact us about a granny flat, the first conversation covers the address of the property, the type of structure you are planning, and what records you have about the main dwelling. From there, we check the applicable planning scheme, confirm the classification and size constraints, and tell you what drawings the council will need.

We produce a full set of plans to the standard required by your council. For most Gold Coast and Brisbane granny flat approvals, that typically includes a site plan showing the location of both dwellings and all relevant setbacks, floor plans and elevations of the proposed structure, and the relevant details required by the applicable code.

We have done this across both council areas since 2016. We know what each council’s planning teams look for and we know which applications come back with requests for more information. Our job is to make sure yours does not.

A Few Questions on Granny Flats in Queensland

Can I rent out a granny flat in Queensland?
A secondary dwelling can generally be rented out on the open market, subject to the applicable planning scheme and any conditions attached to the approval. An auxiliary unit typically has more restricted occupation conditions. The classification of your structure determines the answer, and that classification is confirmed at the planning stage before any plans are drawn.

What does a granny flat approval cost?
The cost of the drawings is separate from the council application fees. We will give you a clear quote on the drawing scope when you contact us. The scope depends on the size and complexity of the proposed structure and which council area the property is in. Council application fees vary by council and by the type of application.

How long does a granny flat approval take?
Approval timelines vary by pathway and council. Where a structure qualifies for code assessment, the process moves faster than a full development application. We will give you a realistic assessment of the timeline before you commit, based on the specific council and the characteristics of the application.

What size granny flat is allowed on my block?
The answer depends on your lot size, your zone, and the specific planning scheme that applies to your council area. Both Gold Coast and Brisbane councils link allowable size to the lot, and overlay conditions on the property can narrow that further. Contact us with the address and we will confirm what applies to your block in the first conversation.

We handle granny flat plans across the Gold Coast and Brisbane. Find out if your block qualifies.