SECONDARY DWELLING AND GRANNY FLAT DESIGN BRISBANE.
Secondary Dwelling and Granny Flat Designer Brisbane
Brisbane homeowners are adding secondary dwellings faster than at any point in Queensland's history. A law change in 2022 removed the restriction on renting a secondary dwelling to non-family members, and the result has been a wave of homeowners turning underused backyard space into rental income, multi-generational living, or long-term capital value.
If you're considering a granny flat or secondary dwelling, Formardå can take you from concept through to council-approved, construction-ready drawings. Andrew Lynch is a QBCC licensed building designer with 17 years of experience and 610 completed projects across Brisbane and Southeast Queensland.
CONTACT.
REQUEST A QUOTE FOR YOUR NEXT PROJECT
We'll get back to you with an estimate.
Site Assessment and Design Brief
Preliminary Design
Every secondary dwelling project starts with a review of your lot. We check your zoning, lot size, overlay coverage, setbacks, and proximity to the existing dwelling before drawing anything. This gives you a clear picture of what's achievable on your specific block before any fees are committed.
We develop concept floor plans and a site plan showing how the secondary dwelling sits on the lot, its relationship to the existing home, car parking, and setbacks. At this stage you can see the layout, review it, and request changes before we move into the detailed documentation phase.
Development Approval Documentation (Where Required)
Building Approval Documentation
Some lots fall outside the accepted development pathway, character overlays, flood zones, atypical lot shapes, or projects that exceed the 80m² cap. Where a DA is required, we prepare the full council submission package including site context analysis, streetscape information, and all council-required supporting material.
For secondary dwellings that meet the accepted development code, the next step is a Building Approval (BA) from a private building certifier. We prepare the full documentation set required for BA submission:
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Site plan with dimensions, setbacks, and lot coverage calculations
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Floor plans showing all rooms and dimensions
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Elevations (all four sides)
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Sections
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Window and door schedules
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NCC compliance notes
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Roof plan and drainage intent
Frequently Asked Questions — Secondary Dwellings Brisbane
Do I need council approval for a granny flat in Brisbane?
Yes, you need either a Building Approval (BA) from a private certifier, or a Development Approval (DA) from Brisbane City Council if your project falls outside the accepted development code. Most secondary dwellings on standard lots meet the accepted development pathway and don't require a full DA, but professional documentation is still required for BA. We handle this.
Can I rent out a secondary dwelling in Brisbane?
Yes. Since 2022, Queensland law allows secondary dwellings to be rented to anyone, not just family members. Your secondary dwelling must still comply with BCC's planning code, including the 80m² floor area limit and proximity requirements.
What is the maximum size of a granny flat in Brisbane?
Brisbane City Council's accepted development pathway allows a maximum gross floor area of 80m² for a secondary dwelling. This is the internal floor space and does not include covered outdoor areas like patios or verandahs (though these may count toward lot coverage calculations depending on your zone).
How long does it take to get a granny flat approved in Brisbane?
For projects on the accepted development pathway, the Building Approval process with a private certifier typically takes 2–4 weeks once the documentation is submitted. Design and documentation preparation takes approximately 4–8 weeks depending on project complexity. Projects requiring a full DA from Brisbane City Council will take longer generally 3–6 months including design, submission, and assessment.
Do I need a QBCC licensed designer for my granny flat?
You need documentation prepared to a professional standard for Building Approval submission. Using a QBCC licensed building designer ensures your documentation meets NCC requirements and BCC's code, and that the certifier has everything they need to issue approval without requests for additional information. Andrew Lynch holds a QBCC Building Design (Medium Rise) licence — Licence No. 15051406.
Can I build a secondary dwelling on a sloping block?
Yes, sloping blocks can accommodate secondary dwellings, but the design needs to respond to the site's fall. A skilled building designer will position the dwelling to work with the slope, manage drainage, and meet setback requirements as measured from natural ground level. We design secondary dwellings on flat and sloping lots across Brisbane.
Get a Quote for Your Secondary Dwelling Project.
01
Design Consulttation &
Design Brief
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Preliminary Design
03
Development Approval
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Builidng Approval
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Building Certifcates
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Project Hand Over
How Much Does a Secondary Dwelling Cost to Design?
Secondary Dwelling Design Across Brisbane
Design and documentation fees for a secondary dwelling in Brisbane typically depend on the size of the dwelling, the complexity of the site, and whether a DA is required.
For a straightforward secondary dwelling on a standard lot meeting the accepted development code, design fees are generally lower than a comparable extension or new home, because the scope is bounded and the approval pathway is clear.
We provide a fixed-fee proposal once we've reviewed your lot and understood the scope. There are no hidden costs and no hourly rates that blow out — you know the design fee before any work begins.
Get in touch with a brief description of your block and what you have in mind, and we'll come back to you with a clear, written fee proposal.
We design secondary dwellings for Brisbane homeowners across the inner suburbs and broader Southeast Queensland. Common areas we work in include the inner west (Paddington, Ashgrove, Indooroopilly), the inner south (Annerley, Yeronga, Moorooka), inner north (Albion, Lutwyche, Clayfield), and across the bayside and outer western suburbs.
Every block is different. Slope, orientation, lot size, zoning, and overlay coverage all shape what's possible and what the dwelling needs to look like to get approved and built. That local site knowledge is what we bring.
What Is a Secondary Dwelling in Brisbane?
Brisbane's Rules for Secondary Dwellings, What You Need to Know
A secondary dwelling — commonly called a granny flat — is a self-contained living space on the same lot as an existing home. It has its own bedroom, bathroom, kitchen, and living area, and is typically used for:
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Rental income (short or long-term)
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Multi-generational living ageing parents, adult children, or family who want proximity without sharing a roof
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Home office or studio with overnight accommodation
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Guest accommodation
In Queensland, secondary dwellings can now be rented to anyone not just family members which has dramatically changed the return-on-investment calculation for Brisbane homeowners.
Brisbane City Council has an accepted development pathway for secondary dwellings, which means most granny flat applications don't require a full Development Approval (DA). They are assessed as accepted development, provided they meet the code.
The Key Rules Under Brisbane City Council's Code
What Formardå Delivers for Your Secondary Dwelling Project
The main planning requirements for a secondary dwelling in Brisbane are:
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Maximum gross floor area: 80m² (including all internal floor space)
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Proximity to existing dwelling: The secondary dwelling must be within 20 metres of the primary home
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Minimum lot size: Your block must meet BCC's minimum lot size requirements for your zone
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One secondary dwelling per lot: You can't build a second granny flat if one already exists on the title
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Setbacks: Must meet the setback requirements for your zone (typically 1.5m side and 6m rear, but this varies)
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Car parking: One additional car space is required for the secondary dwelling
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Flood and overlay requirements: Lots in overland flow paths, flood zones, or character overlays may have additional requirements that affect the design
Meeting these rules doesn't require a DA — but getting the documentation wrong or missing a code requirement can still hold up your building approval. That's where an experienced building designer saves you time and money.
We handle the full scope of design and documentation for secondary dwelling projects — from initial site assessment through to construction-ready working drawings.