By Adam Hubbard April 4, 2025

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The Hidden Cost of Noise: How It’s Quietly Eroding Property Values

Property Market News
The Hidden Cost of Noise: How It’s Quietly Eroding Property Values

Key takeaways

While investors typically focus on location, scarcity, infrastructure, and lifestyle, noise pollution is often overlooked.

Fact is, excessive noise significantly reduces property values, rental performance, and affects residents’ health.

Train Noise: Each 10-decibel increase reduces property values by approximately 4%. Notably relevant near rail lines in major cities.

Road Traffic Noise: Every 10-decibel increase reduces property values by about 6%. Properties near freeways and arterial roads are most impacted.

Aircraft Noise: Homes directly under flight paths experience a 6–9% decline, sometimes even higher. Cairns Airport’s study demonstrated properties under direct flight paths sold for about 17% less than comparable homes outside noise-affected areas.

Integrating noise assessments into investment due diligence is essential, akin to checking flood, bushfire, or electrical infrastructure risks.

In property investment, we talk a lot about location, scarcity, infrastructure, and lifestyle appeal.

But there's one factor that rarely makes it to the front page of feasibility studies — noise.

And yet, mounting evidence suggests that excessive environmental noise isn’t just annoying, it’s measurably reducing property values, undermining rental performance, and even impacting public health.

A recent PropTrack report brings this often-ignored issue into focus, quantifying how noise — from aircraft, trains and major roads — affects both buyer sentiment and market performance.

And as property investors we can no longer afford to ignore it.

Let’s talk numbers: noise and its effect on property values

The PropTrack report analysed the impact of decibel increases from various noise sources across residential property markets.

Here's what the data shows:

Train noise: For every 10-decibel increase, there’s a 4% drop in property values. This is especially relevant for homes backing onto train lines or near busy rail corridors like Melbourne’s Pakenham line or Sydney’s T1 North Shore line.
Road traffic noise: This has a slightly greater impact, with every 10-decibel increase resulting in a 6% fall in value. Think properties adjacent to freeways or major arterial roads.
Aircraft noise: Homes under flight paths suffer a 6–9% decline in value, depending on proximity and frequency of air traffic.

These findings aren’t theoretical, they’re consistent with long-standing global research.

A 2020 study around Cairns Airport, for example, found that properties directly in the airport’s flight path experienced a staggering 17% price discount compared to similar homes outside the affected area.

So, if you're purchasing a $1 million property under a flight path, you could be giving up $60,000 to $90,000 in inherent value, and that’s before factoring in reduced future capital growth or higher rental vacancies.

The rental risk: noise drives tenants away

Note: Investors take note: it’s not just owner-occupiers who are turned off by noise.

The PropTrack report also highlighted significant tenant churn in high-noise environments.

One cited study found that in areas where night-time noise levels exceeded World Health Organisation (WHO) guidelines, rental properties experienced 69% higher tenant turnover over a five-year period compared to quieter areas.

That translates to more frequent vacancies, increased letting costs, and higher wear and tear.

Over time, this erodes your net rental income and increases the management burden, especially in tightly held, high-demand investment suburbs where stable tenancies are crucial to long-term success.

In a time when many investors are focused on cash flow and yield resilience, this kind of instability is not just inconvenient, it's a serious threat to portfolio performance.

Beyond dollars: the health implications of environmental noise

The health impacts of excessive noise aren’t just speculative, they’re well documented.

The World Health Organisation calls environmental noise an “underestimated threat” that contributes to:

Chronic sleep disruption
Increased cardiovascular risk (including high blood pressure)
Impaired cognitive function
Reduced academic and workplace performance
Mental health issues such as anxiety and stress
Long-term hearing damage

Children are particularly vulnerable.

The European Environment Agency reports that more than 500,000 children across Europe experience impaired reading and concentration due to transport-related noise.

Around 60,000 children develop behavioural challenges linked directly to chronic noise exposure from road, rail, and air transport.

While these studies are international, the principles are universal.

In the context of Australia’s increasingly dense urban environments, especially in major capital cities like Sydney, Melbourne, and Brisbane, the conversation around health and liveability is becoming more central to how buyers make decisions.

Western Sydney: a high-profile battleground

The ongoing construction of the Western Sydney Airport provides a timely real-world case study.

Locals have pushed back hard.

Groups like RAWSA (Residents Against Western Sydney Airport) have been vocal in their opposition, citing “24-hour noise”, “toxic air”, and environmental disruption.

These protests are more than just nimbyism.

They reflect genuine concerns about the long-term livability and value of homes directly impacted by flight paths.

In response, the federal government has assured the public that Western Sydney Airport will implement the most stringent noise-related land use planning in the country, with:

Sophisticated flight path design to minimise disruption
Encouragement of quieter, next-generation aircraft
Zoning controls to restrict sensitive buildings (like schools and hospitals) near high-noise zones

But even with these measures, perception matters.

Buyers often act emotionally, and the stigma of “being under the flight path” can linger in a suburb’s reputation, limiting future capital growth and buyer appeal.

Strategic implications for property investors

So what does this mean for those of us building or managing a property portfolio?

Noise exposure must now be factored into due diligence, just as we consider flood zones, bushfire risk, or high-voltage transmission lines.

The impact on value is real.

The loss in rental performance is real.

And so too is the drag on long-term growth.

In practical terms, this means:

Avoiding properties directly under established or planned flight paths, unless deeply discounted or offset by other growth drivers.
Being wary of properties adjacent to freeways or major roads, particularly where barrier infrastructure is lacking.
Checking rail proximity, not just for convenience, but for potential noise intrusion — especially near older, above-ground lines with poor insulation buffers.
Using mapping tools and ambient noise data (like those produced by Ambient Maps) to assess sound exposure with more precision.

At Metropole, we’ve long included these factors in our proprietary research methodology.

While many buyers are still focused on superficial features like a granite benchtop or polished floorboards, we’re looking at the deeper, often invisible issues that affect liveability and long-term performance. and noise pollution is a big one.

Can noise be offset by infrastructure?

Of course, this isn’t a one-sided story.

Sometimes, major infrastructure like an airport or highway brings with it improved job access, better schools, and more transport options, all of which can fuel demand.

In such cases, noise becomes one of many competing variables.

But savvy investors will weigh the trade-offs carefully.

If two suburbs have similar fundamentals, but one sits under a flight path and the other doesn’t, the smart money will follow the silence.

Final thoughts

The Australian property market is becoming more sophisticated, and so too must our investment strategies.

Noise pollution is no longer an afterthought.

It’s a quantifiable factor influencing capital growth, rental stability, and buyer demand.

It affects perception, health, and ultimately, profitability.

As the market continues to tighten and the margin for error narrows, smart investors will use every available data point to make more informed decisions.

So next time you’re considering a property, don’t just walk the block.

Stop.

Listen.

That sound you hear might just be the sound of capital growth slipping away.

About Adam Hubbard Adam Hubbard is a senior Wealth Strategist at Metropole and his many years of real estate and wealth creation experience gives him a holistic perspective with which he helps his clients safely grow their wealth through property.