In this important section, we have outlined the significant stages of the Development Consent Order (DCO) process in sequential order.
They represent our best understanding of how the process could progress. However, if the proposed changes the Government has for statutory consultations for DCOs become law, then no applicant will be required to hold a statutory consultation. Stages 5 onwards could change considerably.
We will add to the content of these pages regularly and, as timings become clearer, add dates.
We will support communities and stakeholders at each stage through additional guidance and creating virtual and / or physical briefings.
Stages
(click boxes to jump to each stage)
Stage 1 - Proposal Submissions
The first formal stage in the process of potential Heathrow Airport expansion will take place on the 31st July 2025, when “scheme promoters”, which will include Heathrow Airport Ltd and others, are expected to submit their proposals to the UK Government.
This submission will include information on the scope, rationale, and potential impacts of the proposed plans. It is a significant milestone that marks the beginning of the formal decision-making process.
We will publish all publicly available information for each of the submissions on the ‘Promoter’ page.
We will build awareness to help communities and stakeholders make an informed response to any consultation on the ANPS.
We will create channels for local residents to ask questions and get further information.
This link takes you to the letter from the Department of Transport to potential scheme promoters.
Stage 2 - Review of the Airports National Policy Statement
Following the submission of the Heathrow expansion proposals, we expect the next critical step in the expansion process will be for the Department for Transport to formally review the need for airport capacity. The document that communicates this is formally known as the Airports National Policy Statement (ANPS).
This National Policy Statement is significant because it sets out the Government’s position about the need for expansion at Heathrow and is approved by Parliament. The statement acts as the primary basis for the planning approvals needed for large-scale expansion, which may include significant redevelopment within the current airport boundary as well as additional runway capacity.
Put simply, the planning process (also known as securing a Development Consent Order) has to review whether any planning application meets the requirements of the Airports National Policy Statement.
Originally designated in 2018, the UK Government’s policy is currently to support expanding Heathrow Airport with a new North West runway. However, since its designation, there have been significant legal, environmental, and policy changes and challenges, including updated climate commitments, air quality standards, and shifts in national aviation demand.
As part of Stage Two, the Department of Transport will:
Assess whether the current policy statement remains valid and up to date, particularly given the evolving legal and environmental standards.
Determine whether changes to the ANPS are required before a Development Consent Order (DCO) application can be considered.
Hold a public consultation if any changes are required, following which a new policy will need to be approved by Parliament.
CISHA will closely monitor this stage and:
Provide clear, factual updates to help communities and stakeholders understand the implications of any changes, and press the Department for Transport for clarity on any issues as required.
Support community engagement, ensuring residents and local organisations are equipped to respond if, as seems likely, public consultation takes place.
This stage is important as the outcome of the Government's review will influence the future direction of the proposed expansion and the legal basis on which any future planning decisions are made.
We are committed to providing independent, accessible, and timely information throughout every phase of this process.
Government guidance on the process for updating national policy statements is here.
Stage 3 - Pre-Application Statutory Consultation
As part of the planning process for a potential Heathrow expansion, the promoter(s) are legally required to carry out a Pre-Application Statutory Consultation.
What is a Pre-Application Statutory Consultation?
A legally required step in the planning process for major infrastructure projects in the UK, such as airport expansions. It happens before the promoter formally submits a Development Consent Order (DCO) application to the Planning Inspectorate.
This consultation gives the public, local authorities, community groups, and other stakeholders the opportunity to:
Review the detailed proposals for the project.
Understand the expected impacts, such as on the environment, transport, noise, air quality, and local communities, including which property is subject to compulsory purchase.
Ask questions, attend public events, and access full information about the plans.
Submit formal feedback (known as representations) that must be considered by the developer and reported on in the final application.
The consultation must follow the requirements set out in the Planning Act 2008, and includes:
Publication of all relevant documents;
Public information events;
Clear explanations of how to respond;
A set consultation period of 28 days.
Before starting the consultation, a key report called the Statement of Community Consultation (SoCC) has to be published. This is a document required by the Planning Act 2008 that outlines how an applicant will consult with the local community about a proposed development.
Feedback from the consultation stage should influence how the final plans are developed and whether adjustments are made, and the promoter has to set out how and why they’ve responded to the feedback as part of their planning (DCO) application. It is a key opportunity to make your views known before any formal application is submitted.
This pre-application consultation is expected to follow some time after the Government’s review of the Airports National Policy Statement (ANPS) and is a critical opportunity for communities, stakeholders, and the public to have their say. It is also the point at which detailed information about the promoter’s plans has to be published.
During this stage, the promoter may;
Present detailed proposals for expansion, including environmental impacts, construction plans, transport links, and mitigation strategies.
Hold public engagement events to explain the plans and answer questions.
Invite formal responses from individuals, local authorities, community groups, and other interested parties.
CISHA’s role will be informed by its remit as set out in the updated Airports National Policy Statement, and could be to;
Build awareness about this consultation, help ensure that communities are fully informed about the consultation process, what’s being proposed, and how to respond;
Provide independent summaries and analysis of consultation materials to support accessibility and understanding.
Encourage and support public participation, especially working to ensure the consultation is accessible to groups who may face barriers to engaging.
Monitor the consultation process to ensure it is fair, transparent, and inclusive.
Recommend additional events or activities where gaps are identified, and scrutinise the Statement of Community Consultation.
Environmental Impact Assessment forms a key part of the process and is a part of consultation. This link is helpful - Nationally Significant Infrastructure Projects: Advice on EIA Notification and Consultation.
Stage 4 - Heathrow Expansion Proposals Finalised following Consultation Responses
Stage Four of the potential Heathrow expansion involves all feedback being reviewed as the promoter finalises its proposals before submitting a formal application for development consent.
The responses gathered during the statutory consultation – from residents, local authorities, community groups, and other stakeholders – must be shown to have been given serious consideration. The promoter is legally required to demonstrate how it has responded to the views and evidence submitted.
During this stage, the promoter will:
Review and analyse all consultation responses;
Update or amend its plans where appropriate;
Prepare a Consultation Report, which is a formal document explaining how each issue raised has been addressed;
Finalise all technical, environmental, and planning documents for inclusion in its Development Consent Order (DCO) application.
This stage sets the foundation for what will be submitted to the Planning Inspectorate for examination. It is essential that the final proposal accurately reflects community concerns and complies with all relevant policy, legal, and environmental standards.
We remain committed to ensuring the process is open, fair, and accessible.
Stage 5* - Final Expansion Proposal Submitted to the Planning Inspectorate
*Likely to change post-legislation.
In this stage of the potential Heathrow expansion, the final proposal – known as a Development Consent Order (DCO) application – is submitted to the Planning Inspectorate (PINS) for consideration.
This submission marks the beginning of the formal examination process for the proposed expansion and must be accompanied by a comprehensive set of documents. It will indicate which properties are subject to compulsory purchase should the consent be granted, although this process will only formally start if the application is approved. It is important that those living and working in this zone are kept informed of what is happening.
The application must include:
The final version of the expansion proposal, incorporating any changes made in response to the consultation;
An Environmental Statement outlining likely environmental impacts;
A Consultation Report detailing how feedback from communities and stakeholders was considered;
A range of technical and planning documents required under the Planning Act 2008.
Local authorities will make formal statements to say if they think the consultation process was adequate. This is part of the legal process.
CISHA will:
Help the public understand what’s been submitted;
Continue to act independently, monitoring whether community voices have been fairly reflected in the application;
Support communities and stakeholders in preparing for the next stage: the public examination of the proposal.
Once the Planning Inspectorate receives the application, it will decide within 28 days whether to accept it for examination. If accepted, this leads to a public process involving hearings, representations, and ultimately a recommendation to Government.
What happens if the application is not accepted?
Application Rejected for Procedural or Legal Reasons
PINS may decide the application is incomplete, non-compliant, or does not meet the legal requirements set out under the Planning Act 2008. Common reasons for rejection include:
Inadequate consultation with the public and stakeholders
Missing or insufficient documentation (e.g. Environmental Statement, Consultation Report)
Failure to follow the Statement of Community Consultation (SoCC)
Weak justification for the need for the project
Application is returned
If the application is not accepted, it is returned to the promoter, along with reasons for the decision. The promoter would then need to:Address the specific issues raised by PINS
Potentially revise and strengthen parts of the proposal
Undertake further consultation or technical work if required
Resubmit the DCO application when ready
Delay to the expansion process
A rejection by PINS would cause a delay to the timeline for any expansion. Expansion cannot legally proceed unless a DCO is successfully submitted, accepted, examined, and approved.Public Transparency
The Planning Inspectorate’s decision – including the reasons for non-acceptance – would be published online, so the public can clearly see what issues were identified.
You can sign up to updates on the Planning Inspectorate on their website.
CISHA will:
· Monitor and explain the reasons for any rejection
· Keep communities informed of any revised proposals or next steps
A refusal to accept the application does not necessarily mean the end of the project, but it is a strong indication that key elements of the proposal or process need to be improved.
Stage 6* - Pre-Hearing Phase – Registration of Interested Parties
*Likely to change post-legislation.
Once the Planning Inspectorate (PINS) accepts the Development Consent Order (DCO) application, the process enters Stage Six: the Pre-Hearing Phase. This stage is a key opportunity for individuals, community groups, local authorities, and other stakeholders to formally register as “Interested Parties” in the upcoming examination of the proposal.
What happens during this stage?
Registration Opens:
The Planning Inspectorate opens a registration period, typically lasting 28 days, during which any member of the public, organisation, or statutory body can register to be involved.
How to Register:
Registration is done via the PINS website using a standard form. Registrants must provide their contact details and submit a brief summary (known as a Relevant Representation) outlining their main points of concern, support, or interest in the proposal.
Becoming an “Interested Party”:
Once registered, you gain the legal status of an Interested Party, which entitles you to:
Submit more detailed evidence later in the process
Attend and speak at hearings
Receive official updates from the Planning Inspectorate
Preliminary Meetings and Hearings:
PINS may also begin to schedule Preliminary Meetings to discuss how the examination will be run, and Issue-Specific Hearings or Open Floor Hearings may follow.
CISHA will:
Inform the public about when and how to register
Provide guidance on completing the registration
Support community groups and individuals to ensure their voices are heard
Continue to analyse and explain developments in a clear, impartial manner
This stage is not yet the examination itself, but it is the gateway to participation. Registering as an Interested Party is the only way to ensure you can fully engage in the next stage of the process.
Stage 7* - Examination Hearings by the Planning Inspectorate (PINS)
*Likely to change post-legislation.
Once the pre-hearing phase concludes and the Planning Inspectorate (PINS) has completed initial preparations, the process enters Stage Seven: the Examination. This is the formal hearing phase, where the details of the expansion proposal is scrutinised in depth.
The examination typically lasts up to six months and is led by a panel of Planning Inspectors known as the Examining Authority.
What happens during the hearing phase?
Detailed examination of the proposal:
The Planning Inspectors will review all submitted documents, including the application, environmental assessments, technical studies, and consultation reports.
Engagement with interested parties:
Registered interested parties – including individuals, local authorities, organisations, and community groups – can;
Submit written evidence
Attend Issue-Specific Hearings on topics like noise, air quality, traffic, and climate
Participate in Open Floor Hearings to share their views publicly
Respond to questions and requests for further information issued by the Examining Authority
The examination is governed by a clear timetable and is conducted openly. All hearings are accessible to the public, and documents are published on the PINS website.
CISHA will:
Support local communities and Interested Parties, helping them understand how to participate and where their voices can be most effective
Further develop its role in light of any updates to the Airports National Policy Statement, and learning lessons from the role that other Airport Consultative Committees have played in DCO applications.
We do not take a position on the expansion itself, but we are committed to ensuring the process is accessible and that community perspectives are heard.
Why this stage matters
The evidence presented, questions explored, and representations made will shape the Examining Authority’s recommendation to the Government on whether to approve the expansion or not.
Stage 8* - The Planning Inspectorate Prepares Its Report to the Secretary of State
*Likely to change post-legislation.
After the examination of the Heathrow expansion proposal concludes, the process moves into the reporting stage. This is when the Planning Inspectorate (PINS) carefully considers all the evidence presented during the hearings and prepares a detailed recommendation report for the Secretary of State for Transport.
What happens in this stage?
Independent Analysis and Assessment
The Examining Authority – the panel of inspectors who led the hearings – reviews:
All written and oral representations from Interested Parties
Technical documents, environmental assessments, and supporting evidence
Issues raised during public and issue-specific hearings
Balanced and Evidence-Based Reporting
The inspectors will assess whether the proposed expansion:
Meets the requirements of national policy (including the Airports National Policy Statement)
Complies with relevant planning, environmental, and legal standards
Adequately addresses the concerns and needs of affected communities.
Recommendation Submitted
The final report is sent to the Secretary of State within three months of the end of the examination. It includes:
A recommendation to either approve or refuse the Development Consent Order (DCO)
Reasons for that recommendation, based on the evidence.
Important: This report is not published immediately. It remains confidential until the Secretary of State makes their final decision.
CISHA will:
Keep communities informed about expected timelines and what this stage means
Explain the process clearly, including what to expect next and how decisions will be made
Although this stage does not involve new public participation, it is a crucial point in the process, as the outcome of PINS’ assessment will strongly influence the Government’s final decision.
Stage 9* - Secretary of State Decision
*Likely to change post-legislation.
Following the Planning Inspectorate’s examination and recommendation, the potential Heathrow expansion process enters Stage Nine: the Secretary of State’s decision. This is the final stage in determining whether consent will be granted for an application for proposed Heathrow expansion.
What happens in this stage?
Decision-Making Authority
The Secretary of State for Transport receives the Planning Inspectorate’s full examination report and recommendation. This report is typically delivered within three months of the close of the examination.
Independent Ministerial Decision
The Secretary of State is responsible for:Reviewing the inspectors’ findings and recommendation
Considering national policy objectives, legal obligations, and wider public interest
Making a final decision to approve or refuse the Development Consent Order (DCO)
Decision Timeline - the decision must legally be made within three months of receiving the Planning Inspectorate’s report, although this timeline can be extended by the Government.
Publication of the Decision - once made, the decision and the full recommendation report are published on the Planning Inspectorate website. This includes:
A clear statement of the decision
The reasoning behind it
Any conditions attached (if approval is granted)
If consent is granted
If the DCO is approved, the promoter would be given legal permission to begin development, subject to any conditions specified. However, construction cannot begin immediately —other regulatory, funding, and preparatory steps would still need to follow.
If consent is refused
If the proposal is refused, the promoter cannot legally proceed with the expansion as proposed. The company could choose to revise and resubmit in future, but any such effort would restart the statutory process.
Stage 10* - Implementation in Line with Planning Conditions
*Likely to change post-legislation.
If the Secretary of State approves the Development Consent Order (DCO) for Heathrow expansion, the process moves into implementation. At this stage, expansion can start to be delivered, but only in accordance with the detailed conditions and obligations set out in the consent decision.
If the promoter is not Heathrow Airport Ltd, detailed agreements would need to be drawn up between the promoter and airport operator.
What this stage involves
Approval does not mean Heathrow expansion can proceed without oversight. The implementation stage is governed by a framework of planning conditions, legal requirements, and monitoring responsibilities, designed to manage impacts and ensure accountability throughout construction and operation.
Key elements include:
Compliance with Planning Conditions
The promoter must follow all conditions imposed as part of the DCO. These may relate to:
o Environmental protection (air quality, biodiversity, water)
o Transport and surface access improvements
o Noise mitigation
o Community impact reduction
o Construction practices and working hours
Approval of detailed plans
Before work begins, the promoter may need to submit further detailed management plans for approval by relevant authorities.[TW1] These must demonstrate how planning conditions will be met in practice.Processes for compulsory purchase
Land which is to be purchased to build the project will be subject to a series of processes. This includes confirming ownership of the land and setting out the dates on which it will be purchased. Purchase values are set out by the Government as part of a national process. Heathrow has set out additional schemes in the past. CISHA will likely have a role of guiding those owning, living and working in the affected areas towards suitable help. Renters in the area should ask their landlords to be kept informed at this stage.
Key Authorities Likely to Approve Detailed Heathrow Expansion Plans
1. Local Planning Authorities (LPAs) - these include the borough councils within which the works will take place
2. Environment Agency (EA) - responsible for approving plans related to:
Flood risk management
Water quality
Waste and pollution control
3. Natural England - reviews and advises on environmental protection plans, especially where biodiversity, protected species, or habitats are affected.
4. Historic England - if heritage assets or archaeological sites are impacted, they may be consulted on heritage mitigation strategies.
5. Highways Authorities / National Highways - approve transport and traffic-related plans, especially where the road network (including motorways or trunk roads) may be affected.
6. Civil Aviation Authority (CAA) - may review airspace change proposals, operational plans, or safety-related requirements.
7. Planning Inspectorate / Secretary of State (in some cases) - in rare instances, certain post-consent approvals might be escalated to the Secretary of State or returned to the Planning Inspectorate for sign-off.
Monitoring and Reporting
Ongoing monitoring will be required throughout construction and operation. Heathrow will need to:
Provide regular updates and data to regulators
Respond to any breaches or community concerns
Demonstrate compliance with agreed standards and commitments
Engagement with Stakeholders
Heathrow and/or construction project leaders are expected to maintain clear communication with local authorities, residents, and other stakeholders during delivery of the project.
At this stage, CISHA will be:
Explaining planning conditions and helping communities monitor compliance with them
Reviewing reports and progress updates
Providing support and signposting guidance to those subject to compulsory purchase
Highlighting areas of concern or potential breach
Providing independent analysis of the implementation process
Keeping communities informed about what is happening and what to expect
Why this stage matters
This is where the real-world impact of the expansion becomes visible. It’s critical that if Heathrow expansion happens, those building it deliver their commitments sensitively, responsibly and in full, to minimise disruption and uphold the public interest.