Queensland has no single state-wide granny flat size limit. Each local council sets its own maximum gross floor area, and the differences between councils can be substantial — the gap between Noosa's 65m² cap and Moreton Bay's 100m² rural allowance is large enough to change what kind of dwelling makes practical sense on a given block. For anyone trying to understand the granny flat size limit in Queensland before investing in design work, the short answer is: it depends on your council. This guide covers the specific floor area caps for Noosa, Gympie, Moreton Bay, and Sunshine Coast, explains the conditions each limit applies to, and flags the most significant recent change — Moreton Bay's October 2024 amendment — so you have real numbers before starting any design conversations.
The Queensland State Position: No Universal Cap, But a Draft Target
Queensland does not have a single state-wide maximum floor area for secondary dwellings. Each local government sets its own limit within the relevant planning scheme, and those limits vary considerably across SEQ.
However, the Queensland Government's Distinctly Queensland Design Series has proposed a draft State Code that would apply a consistent 100m² GFA cap to secondary dwellings on lots above a minimum size threshold. This draft has not been adopted state-wide, and individual councils retain their own rules until any formal adoption occurs.
It is also worth noting what the 2022 state planning amendment did not change. That amendment — made under the Planning Act 2016 — removed the related-family occupancy restriction for secondary dwellings, allowing them to be rented to any tenant. It did not, however, introduce a uniform size cap. The who-can-live-there question and the how-big-can-it-be question are governed by different layers of the planning framework.
Until a consistent state rule is formally adopted, property owners must check their specific council's planning scheme. The figures in this article reflect each council's current adopted rules. Where a proposal has not been formally adopted, that is noted — always confirm current conditions with your local council or a planning consultant before finalising a design.
Noosa Shire: 65m² Maximum, Two Bedrooms, No Infrastructure Charge
Noosa Shire Council caps secondary dwellings at 65m² gross floor area, with a maximum of two bedrooms. Of the four SEQ councils covered here, Noosa sets the smallest floor area limit — but it offsets that restriction with one of the strongest financial incentives in SEQ.
Infrastructure charges are not payable for compliant secondary dwellings in Noosa Shire. In other SEQ councils, infrastructure charges can add tens of thousands of dollars to a project. For a budget-constrained build, therefore, the smaller size limit and the absent infrastructure charge can be a better financial outcome than a larger dwelling subject to those charges elsewhere.
Secondary dwellings in Noosa that meet the size, siting, and zone requirements are classed as Accepted Development — no Development Application required. The project proceeds straight to building certification. On-site car parking must be provided, and the dwelling cannot be subdivided from the primary residence. Rural and Rural Residential zone properties may have additional requirements, so it is worth confirming zone conditions before finalising a layout.
Gympie Regional Council: 70m² and the 20-Metre Proximity Rule
Gympie Regional Council allows secondary dwellings up to 70m² GFA — slightly more floor area than Noosa. However, Gympie applies a proximity requirement that has no equivalent in the other councils covered here.
According to the Gympie Regional Council Secondary Dwellings Fact Sheet (February 2025), the secondary dwelling must be located no further than 20 metres from the outermost projection of the primary dwelling. The rule is designed to maintain a clustered appearance on rural properties — both structures should read as part of the same site when viewed from the road. On a larger lot where the most practical or desirable location for the secondary dwelling sits further from the main house, this proximity rule can directly affect siting options. For Gympie granny flat options and the 20-metre rule explained, those site-specific implications are worth working through before committing to a position on the lot.
Gympie also requires that telecommunications, electricity, and rubbish collection services be shared with the primary dwelling, though a separate water meter is permitted. Secondary dwellings in Residential Living Zones that meet the 70m² size and 20-metre proximity rules are Accepted Development — no Development Application required.
Moreton Bay: The October 2024 Lot-Size-Linked Model
Moreton Bay Regional Council replaced its previous flat cap with a tiered GFA model on 30 October 2024 under the Better Housing Amendment. The new rules link maximum floor area directly to lot size — and the difference between the tiers is significant.
For lots between 450m² and 800m², the maximum GFA is 45m². For lots over 800m², the cap increases to 55m². In Rural and Rural Residential zones, the maximum GFA rises to 100m² — the most generous rural allowance of any SEQ council covered here. According to the MBRC secondary dwellings information page, several additional conditions apply across all MBRC zones: the secondary dwelling must sit within 50 metres of the primary dwelling; separate electricity or water connections are prohibited (sub-meters are permitted, but a single master connection is mandatory); and in Suburban Neighbourhood and Coastal Communities zones, entry points, patios, and decks must face inward toward the primary dwelling rather than toward the street or a side boundary.
For Moreton Bay secondary dwelling options after the 2024 amendment, the lot size is therefore the first variable to confirm before any design work begins.
Sunshine Coast Council: Design Principles Over a Fixed Cap
Sunshine Coast Council's approach to secondary dwelling size differs from every other council in this comparison. Rather than setting a single GFA cap, the Sunshine Coast Planning Scheme requires secondary dwellings to be demonstrably subordinate to the primary dwelling in scale and appearance — consistent with the zone's intended character. There is no simple floor area number to look up.
The proposed new planning scheme actively encourages secondary dwellings in Low Density Residential Zones and removes some previous barriers to greater ceiling heights in residential contexts. Key requirements include deep planted landscapes and gardens around the dwelling, and setbacks that must protect neighbour privacy — with taller structures requiring proportionally larger side and rear setbacks. For landowners considering this council area, working with granny flat builders on the Sunshine Coast who understand the scheme's design principles is important, because design compliance here is assessed more contextually than in councils with a simple size cap.
A building approval is always required for a new habitable secondary dwelling on the Sunshine Coast. Planning approval depends on zone and overlay conditions for the specific lot. Confirming the applicable conditions with a planning consultant or council before committing to a design is strongly advisable here.
Which Council Has the Best Conditions for a Secondary Dwelling?
Comparing the four councils directly, a few practical patterns emerge — though the right answer still depends on individual lot conditions.
For rural or acreage lots, Moreton Bay's 100m² Rural Residential cap is the most generous in SEQ. For standard residential infill lots, Gympie's 70m² limit provides slightly more space than Noosa's 65m², though Gympie's 20-metre proximity rule constrains siting options on larger properties. Noosa, however, offers the best financial conditions for compliant builds — no infrastructure charges — which partially offsets the smaller floor area. Sunshine Coast requires the most careful design work, given the absence of a simple cap and the scheme's emphasis on design consistency with the zone character.
Across all four councils, Accepted Development status is available for compliant builds — meaning most secondary dwelling projects can proceed straight to building certification without a Development Application, provided size, siting, and zone conditions are met. The most important step before committing to any design is confirming the specific lot's zone, any applicable overlays, and whether site-specific conditions affect what is permissible.
For frequently asked questions about secondary dwelling approvals, common approval scenarios across SEQ councils are covered in more detail.
What Fits on Your Block Is the Real Question
Council rules set the outer boundaries of what is permissible. What a compliant secondary dwelling actually looks like on a specific block depends on the lot zone, existing structures, available site area, and any overlays that may apply — all of which vary by address.
The Shed House builds council-compliant secondary dwellings across the Sunshine Coast, Noosa, Gympie, and Moreton Bay regions, offering Kit-Only, Lock-Up, and Turnkey service tiers for secondary dwelling builds. To get a clear answer for your specific property, send an enquiry about your specific property with the address and council zone — that is enough to start a practical conversation about what is achievable within your council's current rules.