Small-lot house rules in Queensland: setbacks for lots under 450 square metres

A small lot under Queensland's state siting rules is a lot of less than 450 m²¹². A lot of 450 m² or more falls under the larger-lot rules.

Under the Queensland Development Code, the small-lot rules apply to detached houses, garages, carports and sheds on lots under 450 m². The larger-lot rules apply from 450 m²³.

A lot of exactly 450 m² is therefore treated as a larger lot under both the existing state rules and the new Queensland Housing Code. The new Housing Code keeps the same 450 m² dividing line⁴.

Brisbane uses the same line for a front lot and adds a second one for a rear lot. Brisbane City Council describes a standard lot as 450 m² or more, a small lot as less than 450 m² , and a rear lot of less than 600 m² as a small lot under Brisbane City Plan 2014⁵.

The state rules also note that council planning rules and other local requirements can apply¹.

Side and rear setbacks under the 2010 rules can become smaller as the lot frontage narrows, regardless of whether the lot is above or below 450 m². Both sets of rules use the same setback table for a rectangular or near-rectangular lot with a frontage of 15 m or less. The standard 1.5 m setback reduces to 0.75 m on a frontage of 10.5 m or less¹³.

For part of the building over 4.5 m and up to 7.5 m high, the setback also reduces as the frontage narrows, from 1.9 m on a frontage of more than 14.5 m to 1.0 m on a frontage of 10.5 m or less¹.

The state rules provide the starting point, but council planning rules can replace some of them. Brisbane does this for small lots. Queensland planning rules allow councils to set different requirements for matters such as setbacks, site cover, building height, privacy, parking and outdoor living space¹⁰. Brisbane City Council states that City Plan provides its own siting rules for lots under 450 m² and that these apply instead of the state small-lot rules⁵.

Brisbane's small-lot code works differently from the state rules. Under the council's rules for a lot of 180 m² or more, the primary street setback is 6 m where every adjoining house sits 6 m or more from the street. Otherwise, it generally follows the closest adjoining setback, but cannot be less than 3 m. Where there is no adjoining house, the setback is 3 m, while garages must be at least 5.5 m from the street¹¹. The same rules set a 1 m side setback for habitable spaces, a 6 m rear setback on a lot deeper than 25 m and site cover ranging from 50 per cent on a lot of 400 m² or more to 80 per cent on a lot of at least 180 m² and under 200 m². Since 18 September 2026, a lot under 180 m² has its own rules: site cover of up to 55 per cent, a 1 m side setback, front and rear wall setbacks that increase with the lot's depth from 3 m and 4 m on a lot less than 15 m deep to 6 m each on a lot deeper than 25 m, and at least 5.5 m to a garage or carport¹².

The council told the state in July 2025 that it uses local rules for setbacks, heights and building location on small lots, and that the draft Housing Code would allow council variations only for building height and car parking¹³. Until Brisbane updates City Plan to state how the Housing Code applies, its existing small-lot rules continue to apply².

Priority development areas have their own development rules rather than the usual state small-lot rules. The 2010 state rules do not apply in these areas, and the draft Housing Code also excludes them¹. In Yarrabilba, Logan, lots from 400 to 450 m² use the state small-lot siting rules, while larger lots use the larger-lot rules. The development scheme also requires at least 16 m² of outdoor living space with a minimum dimension of 4 m¹⁴.

Estate design guidelines can add another set of requirements. North Harbour, at Burpengary East, splits its published setback table at 450 m²: a lot under 450 m² and no deeper than 27 m has a 60 per cent site-cover limit, a 3 m rear setback and a 2 m secondary-street setback. A lot of 450 m² or more has a 50 per cent site-cover limit, a 4.5 m rear setback and a 3 m secondary-street setback¹⁵.

The rules that apply to a small lot in Queensland depend on three main factors:

• Whether the lot is inside a priority development area. If so, the area's own development rules apply instead of the state small-lot rules.
• Whether the council has updated its planning scheme to adopt the Queensland Housing Code. Before that happens, and until 1 September 2029 at the latest, the 2010 state rules or existing council-specific rules continue to apply².
• Whether the registered lot area is under 450 m². Lots under 450 m² use the small-lot rules, while lots of 450 m² or more use the larger-lot rules. Under the 2010 rules, frontage width can also affect the side and rear setbacks.

BuildStreet's fit check uses these same factors. It reads the lot's registered area and frontage width from the cadastre and applies the relevant state rules based on the lot size. It assumes an access street and single-storey walls unless the lot's records show otherwise, and displays those assumptions with the figures they affect.

Where a verified priority development area or estate rule set is available, that layer is applied instead of, or alongside, the state rules. Where a council has adopted the Housing Code but the new rules have not yet been added to the system, the state rules for that council area are shown as not yet available rather than estimated.