What the NSW Government’s latest planning change means for builders working in one of the country’s fastest growing corridors.

The NSW Government has quietly removed one of the more frustrating planning restrictions affecting landowners near Western Sydney International Airport, giving the green light to secondary dwellings in areas previously locked out of that option.

Under amendments to the Western Parkland City State Environmental Planning Policy, homeowners on land within the Australian Noise Exposure Concept 20-25 contour can now build granny flats and studios on their properties. The change applies to eligible land across five local government areas: Wollondilly, Camden, Fairfield, Liverpool and Penrith.

For builders working in Western Sydney, this is not a headline reform. But it is a practical one. And in a market where new work is hard won, practical matters.

Why Secondary Dwellings Matter Right Now

Secondary dwellings punch above their weight in the residential construction pipeline.

They are relatively quick to build. They do not require land acquisition. They can be approved faster than a full residential development. And demand for them is consistent, driven by multi-generational households, adult children who cannot afford to move out, ageing parents who want to stay close to family, and homeowners looking to generate rental income.

For smaller volume builders and specialist granny flat operators, these are bread-and-butter projects that provide steady cash flow between larger builds.

The previous blanket restriction on secondary dwellings near the airport had effectively locked out this work for landowners who sat inside the noise contour boundary, even in areas where projected noise levels were relatively modest. That distinction is what the new planning amendment addresses.

The ANEC, which stands for Australian Noise Exposure Concept, is a long-term planning tool that maps forecast noise levels based on different operational scenarios for the airport, including the potential future addition of a second parallel runway. The 20-25 contour identifies areas expected to experience lower levels of aircraft noise. It is not the flight path. It is the planning buffer beyond it.

Allowing secondary dwellings in those lower-noise areas, while maintaining the restriction in higher-noise zones, is a sensible calibration. The blanket approach was always a blunt instrument in an area with significant variation in actual noise exposure across different streets and suburbs.

What Builders Need to Know

The changes come with conditions, and builders quoting on work in these areas will need to factor them in from the start.

Secondary dwellings approved under this change are capped at 85 square metres. That is consistent with the standard granny flat allowance across much of NSW, so it should not surprise anyone already working in this space.

The more notable requirement is acoustic. Properties built under this approval pathway must include aircraft noise attenuation measures. The media release specifically calls out double-glazed windows as an example.

Get the acoustic specification right early. Document it in your quote and your contract. It protects the client, it protects the build, and it protects you.

This is worth paying attention to at the quoting stage. Acoustic attenuation requirements add cost. Double-glazed windows are not extravagant, but they are not the standard specification either. In a market where clients routinely push back on anything that does not look like a standard inclusion, builders who do not clearly explain why the specification exists risk being undercut by someone who does not, until the certifier picks it up.

The change applies to land in Wollondilly, Camden, Fairfield, Liverpool and Penrith local government areas. Builders working across this corridor should check specific site eligibility before quoting, as not all land within those LGAs will sit within the relevant ANEC contour. Confirm the overlay before you commit to a price.

The Bigger Picture for Western Sydney

Western Sydney is carrying a significant share of the state’s housing pressure right now.

The region is among the fastest growing in the country, and it sits at the centre of a major infrastructure program anchored by the new airport. Jobs are being created. Population is growing. Land is being rezoned. But housing delivery, as always, is lagging behind the ambition.

Secondary dwellings are not the solution to a regional housing shortage. Nobody serious is arguing that they are. But they are a genuine, low-disruption way to add housing supply on existing residential land, without requiring new infrastructure, new rezonings or long lead times.

For homeowners in the affected areas, the change creates a new option. For builders, it creates a new market. For the region overall, it adds a small but real increment to the housing supply that Western Sydney needs.

Multi-Generational Living Is Driving Demand

Beyond the housing supply argument, there is a more immediate driver for this kind of reform.

Multi-generational living is growing across Australia, and particularly in Western Sydney. Cultural factors play a role. Cost of living factors play a role. The reality of housing affordability for younger adults plays a role.

Families who have been blocked from building a secondary dwelling for an elderly parent, or for an adult child who cannot afford to rent independently, now have a pathway that was not available before.

This is the client base that will be driving enquiry. Builders who understand the life circumstances behind the brief, who can explain the acoustic requirements without making them sound like a problem, and who can deliver within a clear scope, will be well positioned.

It is worth noting that granny flat work has its own disciplines. Tight sites, interface with existing structures, managing client expectations around build time and disruption to their daily life. Builders who have not done much of this work before should price accordingly, including contingency for site conditions that are harder to assess on a residential lot than a greenfield site.

One More Lever in a Complicated Market

Western Sydney is a complicated construction market right now. Infrastructure projects are absorbing significant trade capacity. Cost pressures have not fully resolved. And the pipeline of larger residential developments around the airport creates its own timing and trade availability challenges.

This planning change is not a major market event. It is a modest, sensible reform that removes an unnecessary restriction and gives homeowners in a fast-growing region more flexibility.

For builders operating in Wollondilly, Camden, Fairfield, Liverpool and Penrith, it is worth knowing about. Enquiry will follow. Whether that enquiry converts into viable work depends, as always, on who is ready to quote well, explain the specs clearly, and deliver on what they say they will.

That part has nothing to do with planning policy.

Source note: This article is based on a NSW Government media release dated 19 May 2026. Builders should confirm site-specific eligibility with their local council or a planning professional before quoting on secondary dwelling projects in the affected LGAs.

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Author: TGB Editorial