Granny Flats Brisbane – City Council Rules, Approvals, Costs & Site Requirements
If you're researching granny flats in Brisbane, the first step is understanding what your particular property can support. Building a granny flat in Brisbane can involve City Plan requirements, setbacks, infrastructure, overlays, plumbing and building approvals, so the site should be assessed before you commit to detailed design.
We specialise in custom on-site granny flats and detached extensions, designed around the property, the people who will use the space and the planning, building and site requirements that apply across Brisbane City Council.
Brisbane City Council Granny Flat Quick Facts
This table is a practical starting point only. Brisbane City Plan, the Queensland Development Code (QDC), the National Construction Code (NCC), infrastructure and property-specific overlays can change the outcome for an individual site.
✅ Typical maximum secondary dwelling size
Up to 80 m² GFA is the current Brisbane benchmark for a secondary dwelling, subject to City Plan requirements and site-specific assessment.
✅ Detached extensions
Often a useful alternative where a self-contained secondary dwelling is not the most suitable solution. Different planning and building rules can apply.
✅ Building Approval required
Yes. A secondary dwelling is a Class 1a building and requires building approval through a licensed private building certifier.
✅ Development Approval required
Not always. Planning approval may not be required where the proposal is accepted development and meets the applicable City Plan codes. Overlays, neighbourhood plans or non-compliance can trigger a development application.
✅ Plumbing approval
Generally required for new Class 1a plumbing and drainage work. Brisbane City Council administers plumbing permits and inspections.
✅ Infrastructure charges
May apply where the development generates additional demand and an Infrastructure Charges Notice is issued. Liability depends on the approval pathway and the current Brisbane Infrastructure Charges Resolution.
✅ Typical front setback – standard lot
6.0 m under current QDC MP1.2 for lots of 450 m² or more, subject to the neighbouring-building provisions and any applicable City Plan requirements.
✅ Typical side / rear setback – standard lot
1.5 m for the relevant part of a building up to 4.5 m high; 2.0 m for parts over 4.5 m and up to 7.5 m. Narrow-lot provisions can reduce these figures.
✅ Corner blocks
Special road-frontage and sight-line rules apply. Standard lots generally start at 6.0 m to each road frontage, with a reduced nominated frontage possible for some lots with an average depth of 24 m or less.
✅ Small lots
For lots under 450 m², Brisbane City Plan’s Dwelling house (small lot) code contains Council-specific siting provisions. QDC MP1.1 also provides state setback benchmarks.
✅ Separation from existing home
1.8 m is an important NCC fire-separation threshold between Class 1 buildings on the same lot. Closer separation can be possible where the relevant walls and openings satisfy the NCC fire-resisting provisions.
✅ Parking
On-site parking must comply with the applicable City Plan and QDC provisions. The exact outcome should be checked for the individual property and proposed design.
✅ Can the granny flat be rented?
Yes. Queensland rules allow a lawful secondary dwelling to be rented to someone who is not related to the occupants of the primary dwelling.
✅ Typical Building Approval time – Hive guide
Approximately 4–8 weeks for a typical project. Planning, infrastructure, setback or specialist referrals can extend this timeframe.
✅ Typical construction time – Hive guide
Approximately 5–7 months after approvals, depending on project size, site conditions and the appointed builder’s program.
✅ Common site constraints
Sewer, stormwater, easements, flood and overland flow, character or heritage controls, protected vegetation, slope, retaining walls, narrow access and soil conditions.
❌ Don’t commit to detailed plans before your property has been assessed.
✅ Best first step: 👉 Book Your Complimentary Site Assessment
Do You Need Council Approval for a Granny Flat in Brisbane?
A new secondary dwelling in Brisbane requires building approval, and plumbing and drainage approval will generally also be needed. A separate development approval is not always required where the proposal is accepted development and complies with the applicable Brisbane City Plan requirements.
Zoning, neighbourhood plans, overlays, setbacks, infrastructure or non-compliance can trigger additional assessment. This is why a Brisbane granny flat should be checked against the individual property before detailed design begins.
Related guide: Granny Flat Approval Process – From Site Assessment to Construction
Why Choose Hive Small Homes for Your Brisbane Granny Flat?
Every property is different, so we start by understanding your site, your budget and what you want to achieve. Rather than trying to fit every client into a standard design, we consider the available space, access, setbacks, services, zoning, overlays and other constraints before recommending the most suitable approach.
If you are comparing granny flat builders in Brisbane, it is important to understand how the project is delivered. Hive Small Homes coordinates the preliminary assessment, concept design, working drawings, engineering and approval process; construction is undertaken by the appointed independent licensed builder under the homeowner's building contract.
Our process includes:
• Preliminary site and planning assessment
• Indicative Quote
• Custom concept floorplans
• Soil testing and consultant coordination
• Working drawings and engineering
• Building and plumbing approval coordination
• Detailed pricing before construction
• Construction through the appointed independent builder
• Clear communication throughout the pre-construction process
Brisbane City Council Granny Flat Rules – What You Need to Know
Under Brisbane City Plan 2014, a dwelling house can include two dwellings where one is a secondary dwelling. A secondary dwelling remains subordinate to the primary dwelling on the same lot.
The current Brisbane benchmark for a secondary dwelling is up to 80 m² gross floor area (GFA), subject to the applicable City Plan provisions, zoning, overlays, neighbourhood plans and site constraints. The most suitable size for a particular property may be smaller.
Important 2026 update: Brisbane City Council’s Major amendment package L proposes changes to small-scale housing, including secondary dwellings, site cover, storeys and setbacks. As at 12 August 2026 it remains a proposed amendment and is not yet part of the adopted City Plan. The page below therefore uses the rules currently in force.
Do I Need Development Approval?
Not necessarily. Brisbane City Council advises that a dwelling house can be accepted development where it is in an accepted-development zone and meets the acceptable outcomes of the relevant Dwelling house code or Dwelling house (small lot) code, together with any other applicable codes.
Planning approval can be triggered by zoning, neighbourhood-plan provisions, non-compliance with an acceptable outcome or overlays such as flood, bushfire, biodiversity, heritage, Traditional building character, Pre-1911, significant landscape trees, coastal hazard, landslide, waterways and wetlands.
Building Approval
Yes. Brisbane City Council states that houses, including a dwelling house containing a secondary dwelling, are Class 1a buildings and require building approval. The building approval is generally obtained through a licensed private building certifier.
If the design does not meet an applicable QDC siting standard, the building certifier can seek a referral response from Council for an alternative siting outcome.
Plumbing Approval
New secondary dwellings generally involve plumbing and drainage permit work. Brisbane City Council requires an application for a new Class 1a building where plumbing and drainage work is proposed. A secondary dwelling may not qualify for the fast-track plumbing pathway unless it has dedicated Urban Utilities water and sewer connections that are separate from the main dwelling.
Parking
Parking requirements should be checked against the current City Plan and QDC provisions for the individual property. The required outcome can be affected by the dwelling layout, lot type, access arrangements and other planning controls. For that reason, this page does not present one universal extra-parking number as applying to every Brisbane granny flat.
Infrastructure Charges
Infrastructure charges may apply where development generates additional demand on trunk infrastructure. Brisbane City Council’s current Infrastructure Charges Resolution is No. 15 (2026), which commenced on 1 July 2026. Whether a charge is actually payable depends on the development and approval pathway. If an Infrastructure Charges Notice is issued, it will identify the applicable charge.
Setbacks and Building Siting
Brisbane City Council confirms that the QDC governs standard front, side and rear siting for standard lots, while Brisbane City Plan contains specific siting provisions for small lots. The QDC standards below are the currently mandatory 2010 versions. New Queensland Housing Code MP1.1 and MP1.2 provisions were published on 3 August 2026 but are still listed as pending and are not yet in force.
Property type - Standard lot – 450 m² or more
Front / road - 6.0 m, or an adjoining-dwelling streetscape setback in certain cases
Side - 1.5 m up to 4.5 m high; 2.0 m over 4.5 m to 7.5 m
Rear - Same as side
Corner / important note - QDC MP1.2 applies, subject to City Plan and other property-specific controls.
Property type - Corner lot – 450 m² or more
Front / road - Generally 6.0 m to road frontages
Side - 1.5 m / 2.0 m to non-road boundary depending on height
Rear - Same as side
Corner / important note - If average lot depth is 24 m or less, the nominated road frontage may use QDC Table A1; the other road frontage generally remains 6.0 m. A 9 m × 9 m corner building truncation also applies.
Property type - Small lot – under 450 m²
Front / road - Brisbane City Plan small-lot code must be checked
Side - City Plan small-lot siting provisions apply
Rear - City Plan small-lot siting provisions apply
Corner / important note - QDC MP1.1 provides state benchmarks, but Brisbane City Plan contains Council-specific small-lot siting provisions.
Standard Lots – 450 m² or More
Under current QDC MP1.2, the normal road setback for a detached dwelling is 6 m. Where there are existing dwellings on both adjoining lots, the QDC can allow a road setback that responds to the neighbouring streetscape instead of a simple 6 m line.
For side and rear boundaries, the standard QDC clearance is 1.5 m where the relevant part of the building is 4.5 m high or less. It increases to 2 m where that part is higher than 4.5 m but not more than 7.5 m. For parts above 7.5 m, the clearance increases by a further 0.5 m for every additional 3 m, or part of 3 m.
On rectangular or near-rectangular lots with a frontage of 15 m or less, QDC MP1.2 includes reduced side and rear clearances based on the actual frontage and building height. These narrow-lot provisions should be checked before assuming that 1.5 m applies.
Corner Blocks
For a corner lot of 450 m² or more, the standard QDC MP1.2 starting point is generally 6 m to each road frontage. Where the lot has an average depth of 24 m or less, the local government-nominated road frontage may use the reduced setback in QDC Table A1, while the other road frontage generally retains the 6 m setback.
The QDC also prevents a building or structure more than 2 m high from being built within a 9 m × 9 m truncation at the corner of the two road frontages. In addition, fences, screens, retaining walls and similar structures are generally limited to 1 m high within the separate QDC corner sight-line truncation formed by three equal chords of a 6 m radius curve.
For lots under 450 m², QDC MP1.1 provides a baseline of 3 m to an access place/access street with 1 m to the corner-side street, or 4 m to a collector street with 2 m to the corner-side street. However, Brisbane City Council specifically states that the Dwelling house (small lot) code contains the siting provisions for small lots, so the City Plan rules must be checked for the property before relying on the generic QDC figures.
How Setbacks Are Measured
QDC setbacks are measured from the outermost projection of the building or structure to the property boundary. For a roof, the outermost projection generally means the outside face of the fascia, or the roof structure where there is no fascia, rather than simply the external wall.
Separation from the Existing Dwelling
There is not one universal minimum separation that applies to every granny flat and existing house. The NCC fire-separation provisions are an important part of the design.
Under NCC 2022 Housing Provisions Part 9.2, an external wall of a Class 1 building and its openings must satisfy the fire-resisting provisions where the wall is less than 1.8 m from another building on the same allotment (other than an associated Class 10 building or a detached part of the same Class 1 building).
This means 1.8 m is an important design threshold, not an absolute rule that buildings can never be closer. A closer arrangement may be possible where walls, openings, eaves and other elements are designed to comply with the applicable NCC fire-separation requirements. The private building certifier should confirm the final requirement.
Common Site Constraints
A property can meet the basic size and setback rules and still have other constraints that affect the building location, engineering, approvals and final cost. Common Brisbane issues include:
• Sewer infrastructure – Urban Utilities water and sewer assets can affect the building location and footing design. Building over or near an asset may require QDC MP1.4 compliance, Form 32 advice or a Build Over Asset referral.
• Stormwater infrastructure – Council-owned pipes can be located on private property or within drainage easements. Building over or near Council stormwater can require an RPEQ-designed referral response.
• Easements – registered easements can restrict where work is located or require consent from the easement holder.
• Flood and overland flow – Brisbane’s FloodWise Property Report can identify river, creek, overland flow and storm-tide planning information, including minimum habitable floor levels where applicable.
• Bushfire – the Bushfire overlay can trigger additional planning and building requirements.
• Traditional building character, heritage and Pre-1911 controls – these can affect the location and design of new work and may trigger planning approval.
• Protected or significant vegetation – a permit, arborist input or redesign may be required where protected vegetation is affected.
• Sloping sites – slope can increase excavation, retaining, access and structural-engineering requirements.
• Retaining walls – existing or proposed retaining can affect drainage, engineering and siting.
• Narrow or restricted access – limited access can influence excavation methods, material handling, equipment and site costs.
• Soil conditions – reactive or poor soils can require upgraded footing systems following the soil test.
• Neighbourhood plans and building envelopes – property-specific controls can further restrict the available building area.
• On-site wastewater – relevant on properties not connected to reticulated sewer and can affect the usable building area.
Additional Approval Requirements
Depending on the property and design, additional referrals or approvals may include:
• Build Over Asset / Form 32 – where work is over or near Urban Utilities water or sewer infrastructure under QDC MP1.4.
• Build Over or Near Stormwater referral – where proposed work is over or near Brisbane City Council stormwater or drainage infrastructure.
• Boundary setback relaxation / QDC siting variation – where the proposal does not meet an acceptable QDC or City Plan siting outcome.
• Planning approval – where zoning, overlays, neighbourhood plans or non-compliance trigger code assessment.
• Flood or overland-flow assessment – where the Flood overlay or technical flood requirements apply.
• Character, heritage or Pre-1911 assessment – where the relevant City Plan overlays or heritage controls apply.
• Protected vegetation permit or assessment – where protected vegetation may be affected.
• Plumbing permit and inspections – for plumbing and drainage permit work.
• On-site wastewater approval – where the property is not connected to reticulated sewer.
Identifying these requirements before detailed design can reduce the risk of redesign, consultant delays and unexpected costs.
Granny Flat or Detached Extension – Which May Be Better?
A secondary dwelling is not always the most suitable solution. If the objective is to add bedrooms, a home office, guest accommodation, a hobby room or extra family living space, a detached or linked extension may provide a better outcome for the property and the intended use.
The two options should not be treated as having identical planning or building rules. During the preliminary assessment we can consider the intended use, available building area, services, setbacks and budget before recommending the most practical approach.
Can a Brisbane Granny Flat Be Rented Out?
Yes.
Queensland’s secondary dwelling rules changed in September 2022 to remove restrictions on who can live in a secondary dwelling. A lawful secondary dwelling can now be rented to anyone, regardless of whether they are related to the occupants of the primary dwelling.
The dwelling must still be lawful and comply with the relevant planning and building requirements. Renting a granny flat does not convert it into a separately titled property.
Our Granny Flat Process in Brisbane
1. Preliminary Site Assessment
We review the property, planning controls, overlays and available information to identify any obvious constraints.
2. Indicative Quote
Based on the preliminary assessment and your requirements, we prepare an indicative quote to give you a clear guide to the likely project cost before moving forward.
3. Site Visit
If the indicative quote is within your budget, we arrange a site visit to look more closely at access, services, site levels and the proposed building location.
4. Concept Design
We prepare a concept floorplan designed around your property, requirements and budget.
5. Final Pricing & Contract
Once the concept design is agreed, detailed pricing is prepared and the final scope is confirmed before proceeding to contract.
6. Working Drawings, Engineering & Approvals
The project moves through working drawings, engineering and the required building and plumbing approval process.
7. Construction
Once approvals are in place, construction can commence with the appointed independent builder.
Typical Project Timeframes
The following are Hive Small Homes indicative timeframes only. They are not Brisbane City Council statutory timeframes and can vary depending on the property, consultants, approval pathway and appointed builder.
Preliminary assessment / site visit
Approximately 1–2 weeks
Concept design
Approximately 2–3 weeks
Final pricing & contract
Approximately 1–2 weeks
Building Approval
Approximately 4–8 weeks
Construction
Approximately 5–7 months after approvals
**Projects requiring planning approval, Build Over Sewer or Stormwater referrals, boundary relaxations, character or heritage assessment, flood work or specialist reports can take longer
Custom Granny Flat Designs for Brisbane Properties
A well-designed granny flat should feel like a genuine home rather than simply a smaller version of one. Depending on the site, applicable controls and chosen layout, designs can include:
• One or two bedrooms
• Open-plan kitchen, dining and living areas
• Full bathroom and laundry facilities
• Built-in storage
• Covered decks and outdoor living areas
• Energy-efficient insulation and glazing
• Air conditioning and ceiling fans
• Modern kitchens and bathrooms
We can adapt the concept design to suit different block shapes, site conditions, access constraints and the needs of the future occupants.
Granny Flats for Different Stages of Life
A Brisbane granny flat can provide flexible accommodation for:
• Parents or older family members
• Adult children wanting greater independence
• Extended family
• Guest accommodation
• Home office or hobby space
• Rental accommodation
The best design will depend on who will use the dwelling, how much privacy is required and how the new building relates to the existing home and property.
👉Book Your Complimentary Site Assessment
Not sure what can be built on your property?
Hive Small Homes offers a complimentary preliminary Site Assessment to help identify the planning controls, overlays, setbacks, services and potential constraints affecting your property before you commit to a design.
We review available property information to help identify zoning, overlays, underground services, site constraints and the likely approval pathway. This gives you a clearer understanding of what may be possible before spending money on detailed plans.
Frequently Asked Questions
Can I build a granny flat on my Brisbane property?
It depends on the property’s zoning, overlays, lot size, setbacks, available building area, services and other site-specific constraints. Many proposals can be accepted development, while others require planning approval.
How large can a Brisbane granny flat be?
The current Brisbane benchmark is up to 80 m² GFA for a secondary dwelling, subject to City Plan requirements and the individual property. The practical buildable size may be smaller.
What are the typical front, side and rear setbacks?
For a standard lot of 450 m² or more, current QDC MP1.2 generally starts at 6 m to the road and 1.5 m to side and rear boundaries for the part of a building up to 4.5 m high. Narrow lots and City Plan controls can change the result.
What setbacks apply to a corner block?
On a standard 450 m²+ corner lot, the QDC generally starts at 6 m to the road frontages. If average lot depth is 24 m or less, a reduced Table A1 setback may apply to the nominated frontage. A 9 m × 9 m corner building truncation and separate sight-line controls also apply.
Do I need Development Approval?
Not always. Planning approval is generally not required where the proposal is accepted development and complies with all relevant City Plan acceptable outcomes. Overlays, neighbourhood plans or non-compliance can trigger a development application.
Do I need Building Approval?
Yes. A new secondary dwelling is Class 1a building work and requires building approval through a private building certifier.
Do I need plumbing approval?
New secondary dwellings generally involve plumbing and drainage permit work. Brisbane City Council administers the plumbing permit and inspection process.
Can I rent the granny flat to someone who isn’t a family member?
Yes. Queensland rules allow a lawful secondary dwelling to be rented to someone who is not related to the occupants of the main dwelling.
Can I customise the design?
Yes. The concept floorplan can be developed around your property, intended occupants, preferred layout and budget rather than limiting the project to a single standard design.
Can I see completed Hive Small Homes projects?
Yes. Visit the Projects page to see examples of completed Hive Small Homes granny flats and detached-extension projects.
Can I build over a sewer line?
Sometimes. Urban Utilities assets are assessed under QDC MP1.4. If the building work complies with the acceptable solutions, a private certifier can submit Form 32 advice. Non-compliant work generally requires an Urban Utilities Build Over Asset referral.
Can I build over stormwater infrastructure?
Possibly. Brisbane City Council stormwater can be located on private property or in drainage easements. Building over or near Council stormwater can require an RPEQ-designed referral response and accurate survey information.
What if my block slopes?
Slope does not automatically prevent a project, but it can affect excavation, retaining walls, footing design, access, engineering and overall cost.
How close can the granny flat be to my existing home?
The NCC uses 1.8 m as an important fire-separation threshold between Class 1 buildings on the same allotment. Closer separation may be possible where the relevant walls, openings and other elements satisfy the NCC fire-resisting provisions.
What if my property has an easement?
The easement should be assessed before the concept design is finalised. Its purpose, beneficiary and terms can affect whether and how building work may occur within or near it.
What if I have limited or narrow site access?
Restricted access does not automatically prevent construction, but it can affect excavation methods, equipment, material handling and site costs.
Do I need a soil test?
Yes. A soil test is normally required for the structural engineer to design the footing system for the actual site conditions.
Will infrastructure charges apply?
They may. Brisbane City Council can levy infrastructure charges where development generates additional demand. The applicable charge, if any, depends on the approval and current Infrastructure Charges Resolution.
Official Sources Used to Verify the 2026 Rules
• Brisbane City Council – New house (planning and building approval requirements)
• Brisbane City Council – Building near the boundary
• Brisbane City Council – City Plan online
• Brisbane City Council – Major amendment package L (proposed; not yet adopted as at 12 August 2026)
• Brisbane City Council – Residential plumbing works
• Brisbane City Council – Build over or near stormwater and drainage infrastructure
• Brisbane City Council – FloodWise Property Report
• Brisbane City Council – Protected vegetation
• Brisbane City Council – Infrastructure charges and Brisbane Infrastructure Charges Resolution (No. 15) 2026
• Queensland Government / Business Queensland – Queensland Development Code
• Queensland Government – QDC MP1.1: Design and siting standards for single detached housing on lots under 450 m²
• Queensland Government – QDC MP1.2: Design and siting standards for single detached housing on lots 450 m² and over
• Queensland Government – QDC MP1.4: Building over or near relevant infrastructure
• Queensland Government Planning – Changes to secondary dwellings
• Urban Utilities – Build / construction over or near pipes or easements
• National Construction Code 2022 Housing Provisions – Part 9.2 Fire separation of external walls