Heathrow expansion – facts & figures

Writing a letter to protest Heathrow’s plans? Looking for some verified facts and figures about the airport? We’ve gathered together some reliable information about Heathrow and its impact on the local community. See our Other Campaigns page here for more sources of background on Heathrow expansion.


Heathrow Airport is owned and run by Heathrow Airport Holdings Limited, who are themselves owned by overseas investment funds from Qatar, China and elsewhere – with just 10% owned in the UK’s by the Universities Superannuation Scheme Pension Fund.[1]

Money and Finance

The Airports Commission estimated the cost of building the third runway at between £15 – 17 billion at 2014 prices.[2] Their report also contains some interesting speculation on how the airport might finance a scheme of this size. At the same time, the Department of Transport has stated that “This is a privately-funded proposal and Heathrow will meet the costs of delivering their scheme”.[3]

Yet Heathrow Airport Ltd is heavily indebted. According to their 2017 accounts, borrowings stand at £13.4bn, giving rise to speculation by the Financial Times that the taxpayer may well be asked to contribute to the construction cost.[4] Perhaps difficulty with finance explains why the airport plans to take thirty years to deliver its ‘masterplan’?

How much benefit might we as a society expect for this investment? The Airports Commission assessed this benefit at £11.6bn.[5] However, there’s an excellent review of continuing downward revisions to this figure by the New Economics Foundation showing that there may well be no economic benefit whatsoever – well worth reading.

Who uses Heathrow?

It is a myth that Heathrow expansion is necessary to support British business – and arguably with the continuing growth in virtual technology, demand by business passengers may fall.

The Airports Commission stated that “More than three times as many passengers take flights for leisure as fly on business”.[6] Whilst the report also emphasises the importance of leisure travel, it was published some years ago. Since that time the UK has further reduced its CO2 emissions target to net zero by 2050. The impact of this on the social acceptability of flying will not be known for some time but is likely to reduce the demand for aviation.

It’s estimated that 70% of the total number of flights are taken by only 15% of the population, yet the social, economic and environmental costs of this are borne by us all.[7]

In addition, around 30% of all Heathrow passengers are transfer passengers, who therefore directly contribute very little economic benefit to the UK.[8]


London is already well supported by six international airports, at Heathrow, Gatwick, Luton, Stansted, City & Southend. Even without expansion Heathrow is the seventh busiest airport in the world with over 80m passenger movements a year.[9]

Allowing Independent Parallel Approaches would add a further 25,000 flights a year, but will only be permitted if a third runway is approved.[10] These flights will overfly areas not previously overflown, including Ealing, thereby adding significantly to the numbers of residents newly affected by aircraft noise.

A third runway will further increase capacity in the South East to 130m passenger movements a year, and will support an additional 240,000 flights a year to 740,000.[11] This will further widen the imbalance in infrastructure provision between the South East and other UK regions.

And of course, all of this comes at a huge cost to local residents whilst arguably delivering little economic benefit to the UK.


Airport noise nuisance is measured using a standard known as the 55Lden contour – this is the area where the average noise level over a 24 hour period is 55 decibels or above.

Even before any further expansion, around 750,000 people are affected by aircraft noise associated with Heathrow.[12] This is around a quarter of all people affected by aircraft noise in Europe. The Dept of Transport’s own analysis shows that an additional 92,700 people will be affected by noise from Heathrow expansion.[13] A report in the Guardian, here, expects the situation to be much worse.

Amongst the areas likely to be affected is Richmond Park, itself a haven of peace and tranquillity for thousands of West Londoners.

Residents under existing flight paths rely on runway alternation for respite from noise. However, the Airports Commission reports that “Neither Heathrow scheme would be able to deliver the same level of respite through runway alternation as is currently provided, which sees communities around the airport generally benefiting from respite for half of the operating day. The Northwest Runway scheme would reduce this to a third…”[14]

Noise from night flights is particularly contentious. The Airports Commission recommends a night flight ban from 11:30 pm to 06:00 am[15] whilst Heathrow itself admits that “Members of the public were also supportive of a ban on scheduled night flight with many suggesting it should be longer than 6.5 hours and that it should include all unscheduled aircraft.”[16]

An interesting summary from the American Center for Disease Control recommends a minimum of seven hours sleep a night for adults, rising to 9-12 hours a night for school-age children. Our own NHS identifies seven ways in which good sleep can help your health, including boosting mental wellbeing, and preventing diabetes and heart disease.

Climate change & carbon emissions

Heathrow is already the largest single source of carbon emissions in the UK.[17]

Current carbon emissions from flights using the two runways at Heathrow have been estimated at 20.8 million tonnes of CO2.[18] For comparison, the total CO2 emissions from Jamaica, a small to medium size middle-income country, in 2017 was 9.5 million tonnes.[19]

Just to be clear, the carbon emissions from a single existing Heathrow runway are equivalent to the total emissions from an entire country.

Or as the Airports Commission noted: “Even though aviation currently accounts for less than 7% of the UK’s overall CO2 emissions, air travel has an extremely high carbon cost compared to other sources: flying one passenger from London to New York and back generates roughly the same level of CO2 emissions as the average person in the EU does by heating their home for a whole year[20]

The government’s own figures foresee the UK’s total aviation emissions rising by 4.9 million tonnes CO2 by 2030 if a third runway is developed at Heathrow airport.[21] Yet since that modelling was completed, the UK has reduced its CO2 emissions target further, to net zero by 2050 – with many environmentalists arguing that even this is too late.

A net zero carbon environment has huge implications for our transport, heating, manufacturing and more – a third runway really has no part to play in this future.

Surface air quality

An EU Directive on air quality, incorporated into UK law[22], sets legally binding air quality standards for a range of pollutants, including NO2 and small particulates. The Airports Commission states that “The UK is not forecast to be compliant with the Directive in terms of NO2 emissions in the Greater London Agglomeration area by 2030, even without airport expansion.” The report then highlights that without action to mitigate emissions, Heathrow expansion would not be deliverable within the legal framework.[23] But will any such mitigations be effective – or even relevant after permission for expansion has been granted?

Given this, it is surprising that Heathrow’s masterplan proposes the world’s largest car park, with The Times reporting “Parking for almost 53,000 vehicles will be built as part of a 30-year masterplan, even though the airport insists that expansion can be achieved without any extra cars on the road.[24]

It is also less widely known that aircraft themselves may contribute to ground level pollution. A report from the Department for Environment, Food & Rural Affairs admits “a location such as Heathrow Airport, where aircraft tend to approach the airport from the east (flying over the London conurbation), there is potential for considerable exposure to UFP [ultra fine particles] from aircraft.”[25] Yet London already exceeds its legal pollution limits – should we be further compromising its air quality, knowing the adverse effects of this on people’s health?

Other sources

There is no shortage of information available about the impact of aviation on our environment, our health and well-being, and on our climate. Here are some good places to find out more:

  • Airports Commission. The government sponsored commission charged with proposing a solution to expanding airport capacity in the UK, and putting the case for Heathrow expansion. Its final report of 344 pages can be found here.
  • Wikipedia has a good summary of the issues around Heathrow Expansion here.
  • The Aviation Environment Federation is a UK-based organisation campaigning for aviation’s impacts on people and the environment to be brought within sustainable limits. The AEF can be found here.
  • The Teddington Action Group – an action group for residents in Teddington and surrounding areas against flight noise from Heathrow. TAG have a very informative website here.


[1] Company Information, Heathrow Airport Ltd
[2] Final Report, Airports Commission, p224-226
[3] The Proposed Expansion of Heathrow – a summary, Department for Transport, p16
[4] Who will pay for Heathrow airport’s £14bn third runway?, Financial Times
[5] Final Report, Airports Commission, p147
[6] Final Report, Airports Commission, p65
[7] A fairer way to fly, New Economics Foundation
[8] Facts & Figures, Heathrow Airport Ltd
[9] Preliminary world airport traffic rankings, Airports Council International
[10] Making better use of our existing runways, Heathrow Airport p13
[11] Facts & Figures, Heathrow Airport Ltd
[12] Do 25 per cent of people in Europe affected by aviation noise live near Heathrow?, FullFact
[13] Appraisal of Sustainability: Revised Draft Airports National Policy Statement, Dept of Transport, p22
[14] Final Report, Airports Commission, p183
[15] Final Report, Airports Commission, p10
[16] Airspace and Future Operations Consultation Document, Heathrow Airport, p33
[17] CCC Net Zero Report, Aviation Environment Federation
[18] Preliminary Environmental Information Report, Heathrow Airport, section 9.6.9
[19] List of countries by greenhouse gas emissions, Wikipedia
[20] Final Report, Airports Commission, p65
[21] UK climate advisers issue Heathrow warning, Greenpeace
[22] Air Quality Standards Regulations 2010, UK Government
[23] Final Report, Airports Commission, p193
[24] Heathrow plans world’s biggest car parks for 50,000 vehicles, The Times, 19th June 2019
[25] Ultrafine Particles (UFP) in the UK, Air Quality Expert Group, Department for Environment, Food & Rural Affairs, Section 4.4