As suggested previously, where anticipatory planning powers do not prevent encroachment, there is a role for mitigation. One example of this approach is the adoption of sound insulation schemes by airports. The cases of insulation at Heathrow and Marseille Airports are examined here to explore this type of reactive intervention.
ANIMA undertook to examine, through qualitative research, whether interventions implemented by airports or other stakeholders in airport regions could have an impact on residents’ quality of life . In this study, sound insulation was studied at Marseille and Heathrow Airports. Concerns about aircraft noise impact date back to the 1950s and 1960s when jet engines started to be introduced, and international aviation became more popular . Thus, a key aim of the insulation schemes was to reduce noise complaints and general community dissatisfaction by reducing noise disturbance attributable to aircraft overflights.
Sound Insulation Schemes Studied
In 1997, the French state implemented a specific sound-proofing assistance system for large airports. This meant that residents affected by aircraft noise could then receive a grant for sound insulation for their homes. The system was originally managed by the National Environment and Energy Management Agency and financed by a general tax on polluting activities. Now, the grant is exclusively financed by airlines via a tax on aircraft noise pollution (TNSA), levied by the DGAC (Directorate General of Civil Aviation) according to the “polluter pays” principle. The criteria for eligibility around Marseille Airport are that the accommodation is located inside the annoyance map contoursFootnote 3 and was built before the noise annoyance plan had been created.
In order to explore quality of life and, in particular, the concept of scheme fairness, focus groups were carried out in three areas around Marseille Airport—two in the annoyance noise map and one outside the annoyance noise map contours, following these criteria:
Eligible to the grant/insulated: City of L’Estaque (Marseille airport).
Eligible to the grant / non-insulated yet: city of Marignane (Marseille airport).
Non-eligible / non-insulated: City of Vitrolles (Marseille airport).
The assumption was that people who were situated in the grant area and had already been in receipt of insulation would be more likely to appreciate the intervention than the other participants. Moreover, it was important for us to investigate the perception of those people who could be insulated but had ignored the process of the insulation program. Indeed, it was hypothesised that the insulation scheme is not well known by people, even those who are eligible for it. This could also have an impact on their perception, because it deals with issues of fairness. Finally, the intention was to investigate this kind of intervention in an area with a mild climate, because it was assumed that it would not be as well perceived in comparison to colder areas. It was anticipated that the results could help to better frame the intervention according to the location, that is, that there should be knowledge about the location and potentially a decentralisation of the decision-making bodies.
The annoyance map in Fig. 6 illustrates the range of noise affected areas by different colours.
Another focus group was also conducted in order to consult the people involved in a noise pressure group.
Sound insulation as an intervention to help mitigate aircraft noise impacts around Heathrow began being discussed in the, resulting in a range of schemes being developed over the ensuing 60 years. In the mid-1990s, a voluntary daytime noise insulation scheme was introduced by Heathrow Airport, followed by a voluntary night noise insulation scheme early in the following decade. By 2014, Heathrow had started to offer the Quieter Homes Scheme (QHS) for those residents living closest to the airport within the 69 dB LAeq,16 h aircraft noise contour. An overview of these schemes is provided: Box 2.
Box 2 Brief details of sound insulation schemes at Heathrow Airport
The (Residential) Day Noise Insulation Scheme (or Day Scheme) is based on the 1994 69 dB LAeq,18 h contour and is designed to protect those homes exposed to the aircraft noise in the day, including in the early morning arrival period before 06:00. These properties are eligible to receive 50% of the cost of replacement windows and external doors, or free secondary-glazing, and free loft insulation and ventilation. 9300 homes fall into this scheme’s boundary.
The Night Noise Insulation Scheme (or Night Scheme) is designed to address the impact of night flights on local residents. The scheme boundary is based on the footprint of the noisiest aircraft regularly operating between 23:30 and 06:00. Eligible properties are entitled to receive 50% of the cost of replacement bedroom or bed-sitting room windows, or free secondary glazing of bedroom or bed-sitting room windows, and free loft insulation and ventilation. Approximately 37,000 homes fall within this scheme’s boundary.
The Quieter Homes Scheme (QHS) applies to homes based on the 2011 69 dB LAeq,16 h contour. It covers the full cost of carrying out the work which can include loft and ceiling insulation, double-glazing or external door replacements and loft and ceiling over-boarding. Around 1200 homes located close to the airport are entitled to this scheme (Fig. 7).
Unlike the insulation scheme funding model in France, Heathrow has introduced its range of noise control and mitigation measures voluntarily, since legal instruments related to sound insulation at Heathrow have expired. However, the prospect of statutory action is usually highlighted by the government if appropriate ‘voluntary’ actions are not undertaken at UK airports. For further information about the guidance around voluntary action, please see Box 3.
Box 3 UK Guidance on sound insulation
In the UK, under Sect. 79 of the Civil Aviation Act (as subsequently amended) the government has powers to direct airport operators to implement noise insulation schemes. Although the prospect of statutory action is usually highlighted by government if appropriate ‘voluntary’ actions are not undertaken, Heathrow, Gatwick and Stansted as designated airports, along with many of the larger non-designated airports in the country have introduced their own noise insulation schemes on a voluntary basis or in response to planning conditions/agreements; schemes operated at other UK airports tend to be derived from or closely resemble the designated airport schemes. Such has been the effectiveness of these initiatives that the Government chose not to amend Sect. 79 in light of conclusions to the consultation on the control of noise from aircraft published in 2003.
The UK government remains committed to the idea that aircraft noise problems are best resolved locally and that airport operators should be expected to take all practical steps to ensure that disturbance to those living in the surrounding area is kept to a minimum (: 7). Indications as to what constitutes ‘all practical steps’ can be found in the Aerodromes (Noise Restrictions) (Rules and Procedures) Regulations 2003 that implemented ICAO’s balanced approach outlined above, and more generally in the White Paper of the same year. The ‘balanced approach’ was adopted as EU policy in March of 2002 when the European Parliament and Council approved on the Directive 2002/30/EC on the establishment of rules and procedures with regard to the introduction of noise-related operating restrictions at Community airports.
The White Paper “The Future of Air Transport” , set out a strategy for the future of the industry in the UK that ‘balances’ the desire for growth with the need to ‘reduce and mitigate the environmental impacts of air transport and of airport development’ (p.29). It identified the measures that the government expects airport operators to adopt in order to help those affected by noise when new airport development takes place, these include:
A continuation of the voluntary noise insulation grant schemes which take as their guideline threshold the 69dBA Leq 16 h contour for 2002.
The adoption at larger airports (those with more than 50,000 movements a year), of mitigation measures that:
Offer households who are subject to high levels of noise (69dBA Leq or more) assistance with the costs of relocating; and
Offer acoustic/sound insulation (applied to residential properties) to other noise sensitive buildings, such as schools and hospitals, exposed to medium to high levels of noise (63dBA Leq or more).
Thus, in the UK, the extent and generosity of sound insulation schemes is largely determined by voluntary action. The value of these actions in maintaining/improving relationships with local communities is emphasised in the UK Airport Operators Association’s Environmental Guidance Manual for Airports.
In order to understand peoples’ experience of living in the vicinity of/under en-route paths to/from Heathrow and their views on sound insulation, telephone interviews were carried out in September 2020. While focus groups had been planned for this aspect of the work also, interviews were adopted due to the need for social distancing during the pandemic. Participants were recruited through a local civic group, HACAN (Heathrow Association for the Control of Aircraft Noise) and included ten respondents. This group was purposively selected as their individual membership of HACAN, whose role is to be a voice for those under Heathrow flight paths, indicated that they would have some willingness to discuss issues related to aircraft noise. It should also be noted that there was a likelihood that some of the group may have had a willingness to oppose the airport and its activities too. This is something that the research team were aware of but it was agreed that the group’s views would still provide insight into individual views amongst a small self-selected population. The interviews covered residents’ satisfaction with their area and issues affecting their quality of life, their views about the airport and about the sound insulation offer, and an exploration of the value they placed on the intervention.
Since this was not a randomly selected group of interviewees but a group for whom noise was clearly already a factor, there needs to be a caveat about the representativeness of the results. Nevertheless, this was a motivated group of individuals who were willing to give their time to discuss quality of life in relation to aircraft noise—something that was of immense value to the researchers during continued restrictions due to the COVID-19 pandemic which prevented the initially planned questionnaire and focus group approach.
All ten interviewees were located to the East of the airport and variously affected by westerly arrivals (close in at Hounslow and further out along the arrival path) or easterly departures (one under the flightpath taking 40% of easterly departure traffic). All had been in their properties for long periods, except for one participant who had moved from an area near the airport to one which was even closer and had been surprised by the apparent increase in noise intrusion, feeling that the move had been a mistake (Fig. 8).
Sound Insulation at Marseille and Heathrow—Research Results
The research undertaken at Marseille, involving four focus groups, suggested that insulation.
was useful for lessening the effects of noise in wintertime when windows are closed.
does not have any effect on air pollution caused by aircraft.
seems to be very effective and can reduce stress and fear of crashes when people are inside their home.
improves thermal comfort and contributes to a reduction of household energy bills.
The Marseille results revealed that a sound insulation intervention should take account of not only the indoor noise but also the outdoor noise exposure. In addition, they indicated that it is necessary for attention to be paid to the capacity of the intervention to improve social interactions in the respondents’ residential area and, in particular, at home. The insulation scheme was seen as a good way to avoid annoyance from indoor noise exposure, but it had to be complemented by other interventions, especially when noise impacted areas are situated in a warm climate area (thus decreasing the time spent with closed windows). Despite these findings, the insulation scheme was well regarded by participants who intended to continue to avail themselves of the intervention.
With specific reference to ineligible participants at Marseille, there was varied knowledge of sound insulation. Nevertheless, participants had a favourable attitude to the insulation scheme procedure itself, even though it was considered unnecessary and ineffective for noise outdoors and during the summer period when windows remain open all day. However, they criticised the delineation of the outline of the noise annoyance map. In addition, they suggested that the annoyance map be scalable to reflect the increase in traffic and be reviewed more regularly. This group expressed concern that enough attention was not drawn to the intervention and that its availability and details had not been sufficiently communicated to the general public and potentially eligible people.
At Heathrow, drawing on the qualitative interviews, the research suggested that there was generally a low level of awareness of what the airport does to minimise noise exposure. Unsurprisingly, then, there was a low level of awareness of insulation provision. Participants drawn from the airport amenity group generally agreed with the principle of addressing the experience of the most noise affected, although the means for determining this was criticised: Some either suggesting that conventional noise measures such as Leq did not adequately reflect lived experience of a series of aircraft noise events of greater intensity than the average noise level, or simply that insulation should extend further out geographically and take account of the increase in numbers of aircraft movements over the years.
Only one participant living in Hounslow (beside Heathrow on the dominant westerlies arrival path) was in an area covered by an insulation scheme (night noise scheme). The sound insulation work had been done before the person moved in, and when they tried to have further work done following the conversion of an attic, this was seen by the airport to be outside scheme provision as it was a new alternation. Ultimately, the participant paid for sound-insulated windows which have improved the situation but not fully remedied it.
All Heathrow participants understood the various sound insulation schemes once they were explained (they had been sent in advance an information sheet on the schemes for use during the interview) and the use of Lmax footprint for the night scheme was considered to be sensible. Overall progression of schemes was not readily evident, especially as the more recent QHS only covers a small number of properties. However, the 100% funding available under the QHS was seen as an improvement; although the 50% offer to pay towards insulation in other schemes was seen to be unfair—with participants querying why residents should have to pay to rectify a problem of the airport’s making. Generally, interviewers had to work hard for any evaluative comments about sound insulation as an intervention, with participants feeling it was impossible to provide a view without speaking to those who had been in receipt. Nevertheless, some relevant comments were:
Future airspace plans are more important.
Respite is more of a contribution than insulation.
Description feels technical.
What’s the performance of the insulation provision? (in terms of indoor sound level reduction).
Offer needs to go further for different scenarios (i.e. consider each operational mode as you are exposed throughout the time when on a particular mode).
Full costs coverage is a clear improvement.
Good use of money but other things are important.
Would be concerned about contractors and quality of installation.
Offer makes sense from a business perspective, it ‘looks good’.
Looks good on paper but what’s the real impact?
Can vulnerability be factored into the qualification for insulation?
In terms of land use planning around Heathrow, it is important to highlight that participants were generally happy to acknowledge the economic benefits from living near to the airport, although personal accessibility was less of a perceived benefit. The interviews also raised the negative issues around people who are frequent fliers and wider environmental problems (carbon and emissions). There was universal agreement that noise disbenefits outweighed any positive contribution from the airport to local communities. Much of this conversation was overlaid with concerns about the airport’s expansion through a third runway: the government decision in favour of which was seen to be misplaced, leading to much criticism of named politicians and processes of decision-making, with communities being ‘treated with total contempt’.
The participants described very little direct information from the airport and what little there may have been as tokenistic, leaving people with a feeling of no control. Some had participated in consultations which they felt had had some influence (e.g. over departures after 11.30 pm) but momentum seemed to have waned.
There was a desire to be consulted but there were also fears that the airport would control the agenda and, thus, outcomes. There was clearly room for improvement in communication over how engagement processes can be enhanced to allow for influence over things that currently feel out of control.
Despite being leading airports, current sound insulation schemes at Marseille and Heathrow are not directly designed to target and improve residents’ quality of life. Instead, they would appear to be part of a suite of noise management tools whose effectiveness in deployment is generally unchallenged by the airport and not sufficiently finessed to meet the needs of local people, when asked about what they would value. In attempting to evaluate the impact of these interventions after the fact, it was clear that this is near impossible as perceptions of appropriateness and impact are overlaid by wider perceptions of the operation/performance of the airport and indeed its development plans.
In addition, it is important to highlight that those insulation schemes that have been implemented have not been systematically evaluated. This can lead to repeated implementation of the same intervention in different contexts and/or continuation of interventions that may not be successful and may not result in the desired outcomes. This is an important consideration in respect to land use planning: without effective evaluation, it is impossible to ascertain whether an insulation scheme is of value to the individuals who are in receipt of the intervention. It is, then, likely to be equally unfeasible to establish whether a community vulnerable to encroachment would find value from airport provision of such sound insulation schemes.
Examining the results for the two airports further highlights that there is a high level of variation in available funds for insulation schemes across nations. Thus, conflicting policies and funding models can make comparison of schemes difficult and confusing.
It is also notable that the results from Marseille and Heathrow Airports show different impacts of sound insulation schemes on residents’ quality of life. For example, depending on climate conditions of a region, sound insulation schemes can greatly differ across airports and national boundaries with respect to their impact on people’s lives.
Sound insulation interventions have received substantial coverage in the academic and grey literature. However, with no evaluation of the types of schemes, it is challenging to determine best practice or potential for national experience to be globally applicable. Nevertheless, the results show better management approaches may help to more directly address the needs of local communities. Within this context, evaluation of a sound insulation scheme is essential, especially as such an intervention may not lead to the airport’s desired outcome or may have potential unintended side effects. By evaluating an intervention, such undesirable impacts can be identified on a timely basis, addressed and the intervention improved accordingly. This form of evaluation can lead to the development of best practice for use of sound insulation in the context of land use planning. To contribute to a more holistic offer, which includes effective evaluation, it is also important to foster effective communication and open dialogue between an airport and its surrounding communities. Such steps can help towards successful sound interventions that are fair and of value to residents.