Granny Flats Near Western Sydney Airport: New 2026 Planning Changes Explained
By Adam Murphy, Principal Building Designer, ANS Design
Recent planning changes may create new opportunities for homeowners near Western Sydney International Airport who are considering a granny flat, studio or secondary dwelling.
For several years, some properties surrounding the airport have been affected by aircraft-noise planning restrictions. These controls limited the ability of homeowners to add secondary dwellings, even where a granny flat could provide valuable accommodation for family members or additional flexibility as household needs changed.
On 19 May 2026, the NSW Government announced that the planning rules had been amended to allow small secondary dwellings on eligible land within certain lower-noise areas surrounding Western Sydney International Airport. The change reverses the previous ban in selected locations while maintaining restrictions in areas expected to experience higher levels of aircraft noise.
The changes may be particularly useful for families considering multi-generational living, accommodation for older parents, space for adult children or a more flexible use of their residential property.
However, the new rules do not mean that every property near the airport can automatically accommodate a granny flat. Property location, aircraft-noise contours, design requirements, zoning and site-specific constraints still need to be carefully reviewed before preparing plans or committing to construction costs.
What has changed?
The State Environmental Planning Policy (Precincts—Western Parkland City) 2021, commonly referred to as the Western Parkland City SEPP, has been amended to allow secondary dwellings with development consent on eligible land within the Australian Noise Exposure Concept 20–25 contour, also known as the ANEC 20–25 contour.
The NSW Government has stated that the amendment applies to land expected to experience lower levels of aircraft noise from Western Sydney International Airport. Secondary dwellings will continue to be restricted in areas expected to experience higher aircraft-noise impacts.
This is an important change for some homeowners who may previously have been unable to proceed with a granny flat because of the airport-related planning restrictions affecting their property.
What Is a Secondary Dwelling?
A secondary dwelling is a smaller self-contained residence located on the same property as an existing principal dwelling.
Secondary dwellings are often referred to as granny flats, although they can serve many different purposes. A well-designed secondary dwelling may provide:
- Accommodation for ageing parents.
- A more independent living space for adult children.
- Additional room for extended family members.
- A flexible studio-style residence.
- Space that can adapt to changing household needs over time.
A secondary dwelling is not the same as a duplex or dual occupancy. It remains associated with the principal home and must satisfy the planning controls that apply to the property.
Which Council Areas Are Included?
The NSW Government announcement states that the changes apply to eligible land within the following local government areas:
- Wollondilly
- Camden
- Fairfield
- Liverpool
- Penrith
Importantly, this does not mean that every property within these council areas automatically qualifies. Eligibility depends on whether the land is within the relevant ANEC 20–25 contour and whether the proposed development satisfies the applicable planning and design requirements.
Before starting a design, homeowners should confirm whether their specific property is affected by the amendment.
What Is the ANEC 20–25 Contour?
The Australian Noise Exposure Concept, or ANEC, is a long-term planning tool used to forecast potential aircraft-noise impacts around Western Sydney International Airport.
The NSW Government explains that the ANEC mapping is based on a range of future operational scenarios, including the potential addition of a second parallel runway. The mapping helps planning authorities consider whether proposed development is compatible with the safe and efficient long-term operation of the airport.
The recent amendment applies to eligible properties within the ANEC 20–25 contour. These areas are expected to experience lower aircraft-noise impacts than land within higher-noise contours.
Properties in areas expected to experience higher aircraft-noise levels remain restricted.
How Large Can the Granny Flat Be?
Under the announced changes, secondary dwellings on eligible land will be capped at a maximum of 85 square metres.
This is enough space to create a comfortable and practical secondary dwelling when the design is carefully considered.
Depending on the site and the homeowner’s needs, an 85 m² granny flat may include:
- One or two bedrooms.
- A bathroom and laundry area.
- An open-plan kitchen, dining and living space.
- Storage areas.
- A small study nook.
- Covered outdoor space, where permitted.
- Thoughtful window placement for natural light and privacy.
The most effective layout will depend on the available area, access, orientation, setbacks, private open space and the relationship between the proposed granny flat and the existing home.
Will Noise Attenuation Measures Be Required?
Yes. The NSW Government has stated that secondary dwellings approved under the changes will need to include aircraft-noise attenuation measures, such as double-glazed windows.
Noise attenuation should be considered early in the design process rather than added as an afterthought.
Depending on the property and the applicable requirements, the design may need to consider:
- Window glazing.
- External door selection.
- Building materials.
- Insulation.
- Roof and wall construction.
- Ventilation.
- The orientation of bedrooms and living areas.
- The placement and size of openings.
A good design should aim to meet the required acoustic standards while still creating a comfortable, attractive and practical living environment.
Can the Granny Flat Be Approved Through CDC?
Homeowners should not assume that the usual Complying Development Certificate pathway automatically applies to these properties.
The NSW Planning update states that the amended Western Parkland City SEPP allows secondary dwellings with development consent within the relevant ANEC 20–25 contour. This means that a property-specific planning review is important before choosing an approval pathway or proceeding with detailed plans.
Depending on the property, a Development Application, commonly known as a DA, may be required.
The correct approval pathway can be influenced by:
- The property location.
- Zoning.
- Aircraft-noise mapping.
- Site area.
- Existing development.
- Setbacks.
- Building height.
- Access.
- Bushfire constraints.
- Flooding.
- Easements.
- Sewer and stormwater requirements.
- Council-specific planning controls.
An early planning review can help avoid unnecessary redesign work and reduce the risk of delays later in the process.
Does Every Property Near the Airport Qualify?
No.
The new rules apply only to eligible land within nominated lower-noise areas. Some properties will remain restricted because of their location within areas expected to experience higher aircraft-noise impacts.
Even where a property is within the relevant ANEC contour, the site still needs to be reviewed against the applicable planning controls.
A homeowner should not rely solely on the fact that a nearby property has been approved for a granny flat. Two properties in the same suburb can have different constraints, approval pathways and design opportunities.
Why Early Planning Advice Matters
A granny flat may appear straightforward, but a successful project requires more than selecting a standard floor plan.
Early design and planning advice can help identify:
- Whether the property is eligible.
- The likely approval pathway.
- Where the granny flat can be positioned.
- Whether access is suitable.
- How privacy can be maintained for both dwellings.
- How aircraft-noise requirements may affect the design.
- Whether additional consultants may be required.
- How to make the best use of the available area.
Reviewing these issues before committing to a builder quote or a pre-designed layout can reduce the chance of unexpected costs, redesigns and approval delays.
Designing for Multi-Generational Living
One of the strongest benefits of a well-designed secondary dwelling is the ability to support family members while maintaining a sense of independence.
For ageing parents, the design may need to prioritise:
- Step-free access.
- Wider doorways.
- A practical bathroom layout.
- Easy movement through the home.
- Good natural light.
- Comfortable indoor temperatures.
- Proximity to the main residence without compromising privacy.
For adult children or extended family members, the focus may instead be on:
- Separate access.
- Storage.
- A functional kitchen.
- Privacy between dwellings.
- Outdoor living space.
- Flexible areas that can be used for study or working from home.
There is no single layout that suits every family. A site-specific design can create a better long-term result than a one-size-fits-all plan.
A New Opportunity for Eligible Western Sydney Homeowners
The 2026 planning amendment is a positive step for homeowners in eligible areas surrounding Western Sydney International Airport.
For some families, it may create an opportunity that was not previously available. A secondary dwelling can provide practical accommodation, improve the use of an existing property and help family members remain close to each other as their needs change.
The key is to confirm what applies to the individual property before moving too far into the design or construction process.
How ANS Design Can Assist
ANS Design can assist homeowners who are considering a granny flat, studio or secondary dwelling in Western Sydney.
Services may include:
- Initial property and planning review.
- Early advice on the likely approval pathway.
- Site-specific concept design.
- Floor plans, elevations and supporting drawings.
- Development Application documentation where required.
- Complying Development Certificate documentation where the property and proposal are eligible.
- Coordination with relevant consultants.
- Design responses to site constraints, privacy, access and aircraft-noise requirements.
- Assistance throughout the approval process.
A carefully planned secondary dwelling should not only satisfy the applicable controls. It should also be practical, comfortable and suited to the family members who will use it.
Planning a Granny Flat in Western Sydney?
Recent planning changes may create new possibilities for your property, but eligibility still needs to be confirmed on a site-by-site basis.
Contact Adam Murphy, Principal Building Designer at ANS Design, to discuss your property and the next steps for your granny-flat or secondary-dwelling project.
Work With ANS Design
If you’re planning a new home, alteration, or secondary dwelling, we’d be happy to help guide you through the process.
Adam Murphy
Principal Building Designer
ANS Design
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Adam Murphy, Principal Building Designer
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