A national second home code: what 537 councils already agree on

Who sets the rule, state by state

Council counts are the ABS 2024 local government areas, 537 once the placeholder rows are dropped. The cap is for the main residential zone on a typical urban lot.

How this was counted. Each row is the Size cap entry for that jurisdiction in state-codes.md, with its instrument and clause; council counts from the ABS LGA 2024 allocation file. The 330 is Victoria, South Australia, Western Australia, Tasmania and the Northern Territory added together; the ACT has no councils. select state, count(*) from councils.csv where rule_source = 'state' and state not in ('NSW') group by state

Do councils change it? 48 were read to find out

In the five states and the territory where the state writes the rule, 62 councils were read individually: ten in each state, 18 in the NT, the ACT and three external territories. In Victoria, South Australia, Tasmania, the Northern Territory and the Western Australian Residential zone, none of the 48 changes the size cap. Three WA councils vary it only outside the Residential zone or above 70 m² (Busselton, Swan and Wanneroo), and Kingborough in Tasmania is on an interim scheme with the same 60 m². In New South Wales 8 of 10 councils read do differ, and only upward: LEP alternatives of 20 to 65 per cent of the house, rural permissibility, zone limits. The complying development path (60 m², 450 m² lot) is identical everywhere in NSW.

How this was counted. The differs_from_state column in councils.csv: yes, no or unknown per council, with the council page it was read from. The councils not individually read are marked unknown, never guessed. select state, differs_from_state, count(*) from councils.csv group by 1, 2

Queensland: the outlier, and inside it the surprise

All 77 Queensland councils (78 schemes with Weipa Town Authority) were read from the planning scheme or the council's fact sheet. 35 set a numeric floor area cap, one (Cook) sets a percentage of the house, and 42 set no cap at all, among them Toowoomba, Rockhampton, Mackay's urban zones and almost every outback and Cape York shire. Of the 35 caps, 80 m² is the most common (9 councils), the median is 70 m², the tightest is Moreton Bay at 45 m² and the loosest Mareeba at 100 m². Minimum lot sizes appear in 15 schemes; 62 set none. 72 of 78 schemes make a compliant second home accepted or self-assessable development, so a certifier's building approval is the only approval. The Housing Code adds a building default of 50 m² (60 m² on lots of 1,000 m² or more) from 1 September 2026, binding only once a council adopts it or on 1 September 2029; none had by 16 October 2026.

Every Queensland council's cap, minimum lot and source are side by side on the Queensland caps page, built from the same scheme reads. The site's own cap files agree with the research: 42 of 77 have no cap.

How this was counted. QLD rows in councils.csv: size_cap_m2 (numeric, a percentage, or none in scheme), min_lot_m2 and approval_path, each with source_url and read_on. The same reads feed data/council-caps on this site. select size_cap_m2, count(*) from councils.csv where state = 'QLD' group by 1

The five rules a national code needs

Written from what the eight jurisdictions already do, not from what anyone wishes they did. Six of them already run on four of the five.

1. One size: up to 80 m². Victoria moved to 80 m² on 14 October 2026, the ACT has been at 90 m² since 2014, the Northern Territory allows 75 to 100 m², and 80 m² is the most common cap among the 35 Queensland councils that set one (9 of them). Every 60 m² cap in the country is being raised or worked around: South Australia 60 to 70 in 2024, Victoria 60 to 80, Tasmania 60 to 90 at hearing, and NSW councils use LEP percentages of up to 65 per cent of the house to get past 60.
   Behind the number: state-codes.md, the Size cap row in each section; summary.md table 4
2. No minimum lot. South Australia, Western Australia, Tasmania, the Northern Territory and the Queensland state rule set none; WA deleted its 350 m² floor in April 2024. Victoria's 300 m² and NSW's 450 m² are triggers for the no-permit path, not bans. Of 78 Queensland schemes, 62 set no minimum. The house's own setbacks and site cover already decide what fits.
   Behind the number: state-codes.md, the Minimum lot rows; councils.csv, min_lot_m2 for QLD rows
3. Anyone can live there and rent it, on the same title. Eight of eight jurisdictions. The last holdout, Queensland, changed on 23 September 2022 (Planning (Secondary Dwellings) Amendment Regulation 2022). None lets the second home be sold on its own title.
   Behind the number: state-codes.md, the Who can live there rows; summary.md point 5
4. No planning permit when it meets the code, only a building approval. Already the law in Victoria, WA, Tasmania and the NT. In Queensland the Planning Regulation bars councils from making a compliant dwelling house assessable in most residential zones, and 72 of 78 schemes make it accepted development. NSW gets there through a complying development certificate. South Australia and the ACT are the two that still require consent every time.
   Behind the number: state-codes.md, the Approval path rows; councils.csv, approval_path for QLD rows
5. One rulebook per state, published as data, with overlays as the only local layer. Six jurisdictions already work this way (VIC, SA, WA, TAS, NT, ACT): the state writes the rule, the council map adds flood, bushfire and heritage. NSW needs its 128 LEP clause 5.4(9) variations read once; Queensland needs its 77 schemes read once, which this site has done. After that, what fits a block is a lookup, not a research project.
   Behind the number: summary.md, headline 1 and the five rules; the 77 scheme reads in data/council-caps

Lines that can be quoted

Six of Australia's eight states and territories already set one granny flat rule for every council. That covers 330 of the 537 councils, 61 per cent. In those states 48 councils were read one by one and none changes the size cap.

Every size cap changed in the last three years went up: NT 50 to 75 in 2023, SA 60 to 70 in 2024, Victoria 60 to 80 in October 2026, Tasmania 60 to 90 at hearing. The country is converging on 80 m² without anyone saying so.

Queensland is the one state where the council decides, and 42 of its 77 councils decided nothing: their schemes set no size cap at all. The other 35 range from 45 to 100 m², with 80 the most common.

All eight jurisdictions let anyone live in or rent a second home on the block. The last to change was Queensland, on 23 September 2022. Occupancy is settled; size and process are not.

Attribute to Big Small Haus Research with a link to this page. The data behind any line is available on request: howdy@bigsmallhaus.au.

Sources and method

Primary sources only: legislation registers, state planning portals, the state code or policy text, and council planning schemes and fact sheets, read on 15 and 16 October 2026. Every state rule carries its instrument, clause, URL and read date in the research file; every council is one row in the CSV with its source and read date. Where a state legislation site refused automated reads, the clause rests on the department's own explainer and council citations, and the research notes say so.

Published by Big Small Haus Research, part of Big Small Haus Pty Ltd, a licensed Queensland builder (QBCC 15506005). The site reads rules and prices; it does not lobby for any maker, builder or council.