Aircraft noise after dark hits airport neighbours hardest, DfT study finds

Night-time aircraft noise may have a much greater impact on the wellbeing of airport neighbours than daytime flying, according to a previously unpublished study commissioned by the UK Department for Transport (DfT).

The research, obtained through a freedom of information request by the New Economics Foundation, estimated that for households without access to subsidised noise insulation, one additional decibel of night-time aircraft noise at 49 dB carried a wellbeing cost of around £2,800 per household per year. At 56 dB, that rose to about £4,000.

By comparison, another decibel of daytime noise at 54 dB was valued at £187 per household per year, rising sharply with existing noise exposure.

The figure is not a direct financial cost. It is a valuation designed to help the government account for the effect of aircraft noise when weighing the costs and benefits of airport expansion.

DfT study finds night noise has greater impact

Simetrica Jacobs completed the Aviation Noise & Subjective Wellbeing report for the DfT in March 2021, but it was never published.

The government told NEF that the report was not taken forward because work was reprioritised during the Covid-19 pandemic. NEF noted that it was therefore unavailable to decision-makers considering expansion at airports including London City, Stansted, Luton and Gatwick.

The research examined residents around Heathrow, Gatwick and Stansted. It found a “strong negative relationship” between aviation noise and subjective wellbeing, with the impact increasing as noise exposure rose and being greater at night.

For daytime noise, the estimated annual wellbeing cost of another decibel rose from £187 at 54 dB to £767 at 56 dB, £1,362 at 58 dB and £2,597 at 62 dB.

At night, the estimated cost was around £2,800 at 49 dB and £4,000 at 56 dB.

These are hypothetical monetary valuations designed to express lost well-being in a form suitable for government cost-benefit analysis.

Noise insulation could make a major difference

Researchers found the negative relationship between aircraft noise and wellbeing only among households that did not qualify for subsidised noise insulation.

For households eligible for insulation schemes, the effect was not statistically different from zero. The report said this suggests insulation schemes may reduce the wellbeing impact of aircraft noise.

However, researchers did not know which households had actually installed insulation or what type was used. They therefore recommended further study.

Leeds Bradford Airport recently proposed a Night Noise Insulation Scheme that would include funding for bedroom air conditioning, as well as for glazing and ventilation improvements.

Air conditioning would allow residents to keep windows closed during warmer nights, helping maintain sound insulation. The airport is also proposing a noise-based Quota Count system intended to encourage quieter aircraft.

CAA study finds annoyance at lower noise levels

The unpublished report predates the Civil Aviation Authority’s Aviation Noise Attitudes Survey 2023–2024, published in June 2026.

The DfT-commissioned CAA study surveyed communities around 10 UK airports and found high levels of annoyance at substantially lower noise levels than in the previous 2014 survey.

Around 10% of respondents were classed as highly annoyed at about 43 dB, compared with 54 dB in 2014. At 50 dB, 19.5% were highly annoyed, rising to 40.6% at 60 dB and 66% at 70 dB.

The UK’s current daytime Lowest Observed Adverse Effect Level is 51 dB, suggesting substantial annoyance can occur below the existing policy threshold.

The CAA did not suggest that people have simply become more sensitive to aircraft noise since 2014. The two studies used different methods. Other factors, including Covid-era flight reductions and increased home working, may also have affected residents’ attitudes.

First night-noise study finds sleep effects below current threshold

The DfT has also published the first part of its separate Aviation Night Noise Effects study.

The first phase surveyed 4,183 residents around eight UK airports and measured self-reported annoyance and sleep disturbance caused by aircraft noise.

Around 10% reported being highly sleep-disturbed at 44 dB, rising to about 20% at 49 dB and to around 20–28% across the 49–60 dB range.

Researchers said 44 dB could be considered a potential night-time Lowest Observed Adverse Effect Level (LOAEL) for sleep disturbance, slightly below the government’s current 45 dB threshold.

The study also found that sleep disturbance between 01:00 and 06:00 could occur at lower noise levels than the eight-hour average suggests. That finding suggests policy should consider the timing of flights as well as overall noise exposure.

This is only the first of two parts. The second ANNE study, expected to be published later in 2026, uses physiological measurements to examine whether individual aircraft noise events cause actual awakenings. Researchers will also measure sound inside participants’ bedrooms, allowing them to compare indoor and outdoor noise with objectively measured sleep disruption.

Schiphol tightens enforcement of noisy night-time flights

The Netherlands is already taking tougher action against noisy night operations.

The Human Environment and Transport Inspectorate (ILT Aviation Authority) announced on 26 August that it had imposed penalty orders on DHL, El Al and Turkish Airlines for breaching Schiphol’s night restrictions despite previous warnings.

Noisier aircraft have been prohibited from taking off or landing at Schiphol between 23:00 and 07:00 since November 2025 to ensure residents near the airport can sleep without noise disturbance.

The airlines have previously violated these restrictions and received warnings. Although they have not yet been fined, the penalty order serves as a final warning from the Authority. Further breaches would trigger penalties of €17,000 per violation, up to €170,000.

What noise means for airport expansion

The Simetrica Jacobs study was commissioned to help the DfT incorporate aircraft noise into policy cost-benefit analysis.

Its findings suggest that treating each additional decibel similarly could underestimate the impact on communities already exposed to high noise levels. They also underscore the greater impact of night operations.

Together with the latest CAA and ANNE research, the evidence points towards a structured approach to airport noise policy that combines quieter aircraft, better insulation and tighter controls on the noisiest night flights. Such a policy might allow airports to grow without increasing the burden on surrounding communities.