NSW Housing SEPP and Airport Granny Flat Rules Explained
The NSW Housing SEPP and airport planning provisions need to be read for the particular proposal. The May 2026 announcement isn’t a statewide increase of the standard granny flat size limit.
The NSW Government announcement of 19 May 2026 describes secondary dwellings up to 85 square metres on eligible ANEC 20–25 land, with aircraft noise attenuation. It names parts of Wollondilly, Camden, Fairfield, Liverpool and Penrith. This is targeted permission, not an approval for every property in those council areas.
Identify the instrument and approval route
The NSW secondary dwelling guidance explains the Housing SEPP framework. The airport announcement concerns Western Parkland City provisions. Ask the planner to identify which provisions apply and how any interaction between them is resolved.
We have removed the earlier simplistic claim that one instrument always supplies the defaults whenever the other is silent. That isn’t a substitute for reading the current provisions and their application to the land.
CDC eligibility is a separate question
Permission for a land use doesn’t establish that complying development is available. Ask whether all requirements for that route can be met, with the relevant constraints and design considered together.
If complying development isn’t available, don’t assume a development application must succeed. The next question is whether another lawful route exists for that specific proposal. Obtain that answer before commissioning a full drawing package.
Existing buildings need their own review
An announcement about secondary dwellings doesn’t certify an existing shed or studio for residential occupation. Supply its approval history and describe the intended conversion so the practitioner can identify what assessment and building work are needed.
Keep the old and proposed uses distinct in enquiries. A drawing labelled “studio” may describe a workroom in one document and a self-contained dwelling in another. State whether it includes sleeping, cooking and bathroom facilities.
Our garage conversion guide sets out the building questions to raise alongside planning. It can’t determine whether your existing structure can be approved.
Questions to resolve before proceeding
Does the announcement approve my design?
No. Obtain advice on the current rules and the proposed building for your property. The announcement explains the policy change; it isn’t a site approval or a construction specification.
Where should I start?
Read our NSW approval overview, then take your address, title details and project brief to the relevant practitioner. Ask for the source and date of the rules used in their assessment.
By The Granny Flat Guide Team. Last updated October 2026. About our research · Project budget calculator
Primary sources
These cards are an editorial summary of official pages. The Granny Flat Guide is not a certifier, council or licensed builder. Check the live official URL before you lodge or sign.
- Your Home (Australian Government)Your Home: Australia's guide to environmentally sustainable homes
- Australian Building Codes BoardNational Construction Code
- Victorian Building AuthorityBuilding Act 1993 / small second dwelling settings
- QBCC (Queensland)Queensland Building and Construction Commission licensing
See our editorial standards for how we research and update guides.
