Secondary Dwellings in Queensland: Planning Regulation 2017 and Council Scheme Rules

What it is

A secondary dwelling in Queensland is a dwelling on a lot that is used in conjunction with, but subordinate to, the principal dwelling on the same lot. The Planning Regulation 2017 (Qld) Schedule 24 sets that definition and treats the unit as a dwelling house for development assessment purposes. The Planning (Secondary Dwellings) Amendment Regulation 2022 commenced on 26 September 2022 and changed two things at once. It removed the long-standing occupancy restriction that required the secondary dwelling to be lived in by a relative of the primary household. It also reclassified the secondary dwelling as accepted development under the State Code on most lots that meet the size and siting tests [1][2].

The product is commonly called a granny flat. Builders sometimes still hear the older term auxiliary unit, particularly in council schemes that pre-date the 2022 reforms. The auxiliary unit definition is being absorbed into the secondary dwelling category as councils update their planning schemes, although a small number of legacy schemes still distinguish the two.

Why the 2022 reforms matter for residential builders

Before 26 September 2022, a secondary dwelling on most lots in Queensland triggered impact assessable or code assessable development. The owner needed a development approval, which added cost plus time to every granny flat project. After the reforms, the State Code for a Dwelling House that is a Secondary Dwelling applies and most projects sit in the accepted development category, provided the unit meets the State Code performance outcomes [3].

Builders should still check the council planning scheme. The State Code overrides inconsistent local provisions for the matters it covers, but zoning, character overlay plus traditional building character provisions in many South East Queensland councils still drive design choices.

State Code requirements

The State Code for a Dwelling House that is a Secondary Dwelling sets the performance and acceptable outcomes for a secondary dwelling that wants to be accepted development. The headline rules cover a gross floor area cap, maximum height, setbacks plus the requirement that the dwelling remain on the same lot as the principal dwelling and not be on a separate title [3].

The State Code is part of the Planning Regulation 2017 schedule structure. The Department of State Development, Infrastructure, Local Government and Planning publishes the consolidated code together with the supporting guidance [3].

Building approval is still required

Removing the planning trigger does not remove the building approval requirement. Every secondary dwelling needs a building approval from a private certifier or a council building surveyor under the Building Act 1975 (Qld) plus the Building Regulation 2021 (Qld). The certifier checks compliance with the National Construction Code Volume Two, fire separation from the principal dwelling, smoke alarm coverage under Queensland's interconnected alarm rules plus the Plumbing and Drainage Act 2018 (Qld) requirements for new fixtures.

QBCC licensing also applies. The builder must hold a Builder Open or Builder Low Rise licence depending on the contract value and scope. The QBCC publishes the licence class requirements together with the maximum contract values that each class can take on [4].

Contracts and consumer protection

Queensland uses two parallel contract regimes. Work valued above $3,300 generally needs a written contract under the Queensland Building and Construction Commission Act 1991 (Qld). Domestic building work above the higher value threshold has to use a Level 2 Regulated Contract that meets the requirements in Schedule 1B of that Act [4]. The QBCC publishes plain English consumer guides that builders should hand to owners before signing.

Common compliance traps

Three issues turn up repeatedly on secondary dwelling jobs in Queensland. The first is treating the unit as a standalone dwelling, which the State Code does not permit. The second is putting the secondary dwelling on a separate meter without first arranging the supply and metering agreement with the relevant distribution business. The third is missing the Home Warranty Insurance premium under the Queensland Home Warranty Scheme; the QBCC requires the premium to be paid before the work starts for contracts above the threshold [4].

Renting the secondary dwelling

The 2022 amendment regulation removed the requirement that the secondary dwelling be occupied by a member of the same household. Owners can now rent the secondary dwelling to any tenant under a Residential Tenancies and Rooming Accommodation Act 2008 (Qld) lease. The Department of Housing publishes guidance on the minimum housing standards that apply to rented premises in Queensland, which the unit must meet before first occupation [5].

Short term accommodation use, including holiday letting, is a separate question that depends on the council scheme. Some councils have made-up new local laws to regulate short stay use; the builder should refer that question to the owner's planner.