Agenda item

Enabling works to allow implementation of full runway alternation during easterly operations at Heathrow Airport including the creation of a new 'hold area' at the western end of the northern runway, the construction of new access and exit taxiways, the construction of an acoustic noise barrier to the south of Longford Village and temporary construction compounds. 

The proposed development is subject to an Environment Impact Assessment (Notice under Article 19 of the Town and Country Planning (Environmental Impact Assessment) Regulations 2017). 

Recommendation: Approval 

RESOLVED: That the application be approved subject to section 106, conditions as set out in the report and the information in the addendum.

Enabling works to allow implementation of full runway alternation during easterly operations at Heathrow Airport including the creation of a new 'hold area' at the western end of the northern runway, the construction of new access and exit taxiways, the construction of an acoustic noise barrier to the south of Longford Village and temporary construction compounds.

The proposed development is subject to an Environment Impact Assessment (Notice under Article 19 of the Town and Country Planning (Environmental Impact Assessment) Regulations 2017).

The Area Planning Service Manager and the Head of Environmental Specialists introduced the application which concerned an application at Heathrow Airport. It was noted that the application related to enabling works intended to implement full runway alternation during easterly operations. The proposals included the creation of a new holding area at the western end of the northern runway, construction of new access and exit taxiways, installation of an acoustic noise barrier south of Longford village, and establishment of temporary construction compounds. These works were subject to an Environmental Impact Assessment.

Officers clarified that the application did not propose an increase in the air traffic movement cap set by the Terminal Five decision, nor did it enable airport expansion. The submission was standalone and unrelated to expansion proposals. Detailed plans and constraints maps were presented, highlighting conservation areas, listed buildings, and green belt land. Officers explained the operational context, including the historic Cranford Agreement, which had previously restricted departures over Cranford village. It was noted that the agreement had been formally ended to allow equitable noise distribution and predictable respite periods for affected communities.

The proposed easterly alternation mirrored westerly operations, introducing runway alternation to provide relief from noise. Planning history indicated that a similar application had been refused in 2013 but subsequently approved on appeal in 2017, with consent later lapsing. The current application sought to secure appropriate mitigation measures, including the noise barrier and rapid access taxiways. Due to the significant environmental effects, permitted development rights had been removed, necessitating a full assessment.

Members heard that an extended consultation process had been undertaken, involving 370 letters, public notices, advertisements in local and regional newspapers, and publication on the Council’s website. It was noted that the London Borough of Hounslow had objected, citing insufficient engagement and technical detail regarding mitigation measures. Officers clarified that these concerns had been addressed in the Committee report and Heathrow’s response, and recommended approval of the application with mitigation secured. Amendments to conditions and heads of terms were outlined, including sustainable water management and ultrafine particle considerations.

A petition had been received in objection to the application, and the lead petitioner was in attendance to address the Committee Members. Key points highlighted included:

·         It was stated that the officer’s recommendation was unsound because it relied on an incomplete environmental statement with key impacts either unassessed or assessed using flawed methodologies. Noise, vibration, and ultrafine particle impacts were identified as missing or uncertain, while mitigation measures were deferred, undefined, and ineffective. The proposed increase in departures from approximately 100 per year to over 56,000 was highlighted as a significant concern, exposing the Council to legal risk.

·         It was stated that the application failed to comply with the Environmental Impact Assessment Regulations 2017, as Regulation 26 required a clear and reasoned conclusion on the significance of environmental effects. The environmental statement lacked baseline monitoring for ultrafine particles and vibration, and relied on uncertain modelling and future assessments, making a lawful conclusion impossible.

·         The noise and vibration assessment was criticised for using LAQ averaging, which masked event-based disturbances, and for treating a 3 dB increase as minor despite its acoustic significance. Limited real-world data and absence of baseline vibration monitoring further undermined reliability. The claimed benefits for 62,100 people were deemed questionable due to flawed methodology.

·         Mitigation measures were considered legally inadequate under CIL Regulation 122, as they were undefined, deferred, and disproportionate. Monitoring and compensation were deemed insufficient to make unacceptable impacts acceptable. Specific concerns included reliance on flawed noise contours, lack of low-frequency noise mitigation, and inadequate vibration measures.

·         The lead petitioner requested that the Committee either refuse the application or defer determination until baseline monitoring, and a complete environmental statement were provided. This approach was presented as evidence-led and procedurally sound, rather than anti-development.

Representatives of Heathrow were also in attendance and addressed the Committee Members. Key points highlighted included:

·         It was noted that the application involved no increase in flights or passenger numbers but required significant runway works and a noise barrier, representing substantial costs to Heathrow. It was confirmed that the application had been submitted to fulfil Heathrow’s commitment to introduce easterly alternation following the government’s decision to cancel the Cranford Agreement, which had created an inequitable situation since the 1950s by subjecting tens of thousands of households to continuous overflying during easterly operations.

·         Heathrow reaffirmed its pledge to implement easterly alternation as soon as practicable, subject to planning consent, with completion targeted for 2028. This commitment was embedded in Heathrow’s People and Planet Strategy and Noise Action Plan. It was noted that the environmental statement had been fully scoped with Borough officers and reviewed by legal and technical experts. It was stated that the application would deliver fairness and equity, providing 62,000 people with predictable respite from overflying for half of each day, regardless of wind direction.

·         It was acknowledged that a smaller number of communities previously protected under the Cranford Agreement would experience change. To address this, noise insulation exceeding government policy requirements and additional mitigation measures for newly affected areas were being offered.

·         Regarding Longford, it was stated that the impacts had been taken seriously, and that Heathrow had engaged with residents early, held meetings and public exhibitions, and conducted a postal survey regarding the noise barrier design. The airfield works had been designed to minimise impacts on Longford, and the barrier would be installed first to reduce construction and operational noise. The barrier was expected to slightly reduce ground noise compared with current levels. On easterly operations, it was confirmed that Longford would experience take-offs for 50% of the day instead of landings, equating to approximately 15% of the year, with noise increasing by less than one decibel. Longford already qualified for full noise insulation, with 470 properties eligible and 70% completed.

·         Air quality impacts were assessed as negligible, with no increase in flights and only a minimal change in ground emissions. However, Heathrow committed to installing a new ultrafine particle monitor in Longford—one of only six in the country—and to collaborate with officers on an air quality plan for the area

In response to the lead petitioner’s submission, the Head of Environmental Specialists acknowledged residents’ concerns regarding ultrafine particles (UFPs) and confirmed that the impact had been recognised. However, it was explained that no policy framework had previously existed to enable a comprehensive assessment, as the necessary policy backing had not yet been established. Proposals had been secured through the heads of terms, which required compliance and action linked to prevailing UK standards, forming part of an agreed action plan with Heathrow Airport Limited.

In relation to Regulation 26, officers believed that the Environmental Impact Assessment (EIA) satisfied the requirements, as it considered vibration and noise, including assessments based on LAeq, which was the standard metric for aviation noise and had been used in previous cases such as Gatwick and Luton. It was noted that the environmental statement contained a range of methodologies, providing sufficient information to assess noise impacts, and was therefore deemed appropriate and policy compliant.

Regarding mitigation, it was noted that Heathrow Airport Limited had been challenged, and a package of measures considered adequate had been agreed. For vibration, a monitoring process was required, as impacts varied depending on property structure and foundations. Consequently, mitigation was to be applied where impacts were identified. This approach was regarded as fair and reasonable. Concerning UFP monitoring, it was explained that deferring the application until comprehensive monitoring was in place would have caused significant delays, as long-term controls and evidence were needed to establish trends. The existing monitor measured concentrations rather than particle counts, which were necessary for assessing UFP impacts. Further work was required with Heathrow Airport Limited and Defra to ensure robust monitoring.

It was considered that sufficient information had been provided within the environmental statement to support the recommendation. It was also confirmed that ongoing work with Heathrow Airport Limited would ensure mitigation was appropriately targeted and monitoring was robust, as set out in the heads of terms.

Members sought clarifications as to why compensation or mitigation costs differed from those at other airports, despite the same noise level thresholds being applied. In response, representatives of the applicant explained that the differences were attributable to the nature of the projects and what was being sought. It was noted that the Luton and Gatwick schemes involved substantial Development Consent Order applications with significant increases in aircraft movements, and their mitigation reflected the scale of impact and number of affected residents. It was stated that no specific justification for the funding levels at Luton and Gatwick had been identified in the evidence reviewed. Heathrow’s approach was based on its current quieter neighbourhood support scheme, and the proposed amounts were considered sufficient to achieve internal noise level criteria in accordance with British Standards for appropriate living conditions. In summary it was clarified that there was no new air noise in this case, whereas in Gatwick and Luton there had been a significant expansion of the airport.

Members queried the applicant’s approach noting that alternation and its delivery were key elements, as well as compliance with policy and previous inspectors’ decisions. It was explained that, although Gatwick and Luton had gone beyond Heathrow’s measures, the critical point was the significant observed adverse effect level, where full costs were required to be paid. It was confirmed that Heathrow Airport Limited had imposed a cap of £34,000, but officers stated that full costs would be secured through the heads of terms if exceeded. It was further highlighted that the application was Cranford-specific and represented a significant improvement on the previous planning application, with alternation providing additional mitigation. Officers had deemed the measures presented to be adequate.

Councillors questioned whether engagement with Longford residents had been sufficient. The applicant responded that efforts had been made to maximise participation, including two exhibitions in Longford, one arranged at the request of the Residents’ Association, a postal survey, social media engagement, letter drops, and door-to-door visits. Attendance at exhibitions was described as healthy, and it was stated that residents had access to information through multiple channels, including summaries on the Council’s website. When asked whether schools had been contacted, the applicant confirmed that they had.

Committee Members raised concerns regarding enforcement powers if Heathrow Airport Limited failed to deliver mitigation, insulation, or rehousing commitments. Officers explained that, unlike the current noise scheme, the proposed measures would be incorporated into the Section 106 agreement, making them enforceable through planning regulations. It was confirmed that detailed provisions would be included for dispute resolution, complaint handling, and local authority involvement.

A further question was asked by Members about the reliability of vibration data from a 2011 report, given that some instruments listed were outdated. Officers confirmed that a fresh approach to vibration monitoring would be implemented under the Section 106 agreement, using up-to-date equipment and extending beyond the original scope to ensure accurate assessment and appropriate mitigation. It was clarified that the existing report was not redundant but would be supplemented by additional work.

Councillors raised concerns regarding air quality and health impacts, citing local and London Plan policies requiring prevention of unacceptable pollution and mitigation of impacts. They questioned whether reliance on post-consent monitoring and future action plans met these policy tests, given uncertainty around ultrafine particles (UFPs) and the absence of defined mitigation. Officers acknowledged the challenge, explaining that while conventional pollutants were addressed through standard measures and action plans, UFPs lacked scientific and policy benchmarks. It was stated that the World Health Organisation had proposed particle count standards, but these had not yet been adopted nationally. Officers confirmed that robust heads of terms had been secured, linking future action to any forthcoming government standards, and enforcement would be possible through Section 106 if breaches occurred. It was acknowledged that this was not an ideal situation but considered the best achievable outcome under current circumstances. Officers also confirmed that neighbouring boroughs had been consulted and responses addressed in the report, with ongoing engagement offered.

Members noted the potential risk of losing negotiated mitigation if the application were to be refused or deferred. It was observed that, despite objections and concerns, the officers had secured significant improvements compared to previous applications. Councillors concluded that the best possible outcome had been achieved. The officers’ recommendation was moved, seconded and, when put to a vote, approved with three Members voting in favour and two abstentions.

RESOLVED: That the application be approved subject to Section 106, conditions set out in the report and the information in the addendum.