What the Procedural Changes Mean for SME Developers

From 1 April 2026, new procedural rules will apply to planning appeals relating to applications submitted on or after that date. The Planning Inspectorate has issued a revised procedural guide which introduces several changes intended to streamline the appeals process and reduce delays.

The updated guidance can be accessed here:
https://www.gov.uk/guidance/planning-appeals-procedural-guide-for-appeals-relating-to-applications-dated-on-or-after-1-april-2026

While these reforms are largely procedural, they will have meaningful consequences for applicants and developers. For SME developers in particular, the changes reinforce the need for planning applications to be properly scoped, fully evidenced and effectively “appeal ready” at the point of submission.

The Structure of Planning Appeals

Planning appeals are determined through three possible procedures:

• Written representations
• Hearings
• Public inquiries

In practice, the vast majority of appeals are determined through written representations.

Planning Inspectorate statistics show that around 94% of all appeal decisions are made through the written representations procedure, with only a small minority proceeding to hearings or public inquiries.

For example, in the most recent 12-month period the Planning Inspectorate issued:

• 18,743 decisions through written representations
• 836 decisions through hearings
• 405 decisions through inquiries

Written representations are therefore the dominant appeal route and the focus of the new procedural reforms.

Written representation appeals are divided into two categories.

Part 1 Appeals (Expedited Appeals)

Part 1 appeals currently apply to a limited number of development types, including:

• refusal of householder applications
• refusal of minor commercial applications
• refusal of express consent for advertisements
• appeals relating to conditions attached to those types of permission

These appeals are often described as expedited appeals. Local planning authorities typically rely on their existing officer or committee report rather than producing a detailed statement of case, and third party representations are not invited.

Part 2 Appeals (Standard Written Representations)

Part 2 appeals involve a more detailed process. Both parties submit formal statements of case and additional evidence, and interested parties can make representations.

This allows for a fuller examination of the issues in dispute.

Expansion of the Part 1 Appeal Procedure

One of the most significant changes introduced by the new guidance is the expansion of the Part 1 expedited appeal procedure.

A wider range of development proposals will now fall within this route, with the expectation that the majority of these cases will be determined through the streamlined process unless the Inspector considers that a more detailed Part 2 process is required.

The decision on which procedure applies remains entirely at the discretion of the Inspector.

The intention behind this change is clear. The Planning Inspectorate is seeking to determine a larger proportion of appeals more quickly by limiting the volume of evidence and representations involved.

Given that the Inspectorate currently determines almost 20,000 appeal cases each year, even relatively small procedural efficiencies could have a significant impact on overall decision times.

Restrictions on New Evidence at Appeal

A key procedural change relates to the submission of new evidence.

Under the revised guidance (see section 7.3), appellants pursuing a Part 1 appeal will not be able to submit evidence that was not previously considered by the local planning authority when determining the application.

Historically, applicants have often used the appeal process as an opportunity to strengthen their case by submitting additional reports or revised technical evidence. Under the new system this will become significantly more difficult.

There are limited exceptions where new evidence may be accepted, for example where there has been a material change in circumstances. However, the acceptance of such evidence remains entirely at the discretion of the Inspector.

The same restriction also applies to interested parties, meaning that objectors will not be able to submit representations on Part 1 appeals.

The underlying objective of this change is to ensure appeals focus on reviewing the decision that was made rather than introducing a new planning case.

Appeals That Will Continue to Follow the Part 2 Procedure

Despite the expansion of the expedited route, certain types of appeal will continue to follow the Part 2 procedure.

These include:

• non-determination appeals
• appeals relating to listed building consent
• appeals relating to discontinuance notices

These cases typically involve more complex planning or heritage issues and therefore require a more detailed examination of evidence.

The Reality of Planning Appeals

Planning appeals are an important safeguard within the planning system, but they are not guaranteed to succeed.

Planning Inspectorate statistics show that around 30–33% of section 78 planning appeals are allowed, meaning roughly one in three refusals is overturned by an Inspector.

Decision times can also be significant. The median time to determine planning appeals across all procedures is typically around 23 weeks, although written representation cases are often slightly quicker.

For SME developers in particular, this means appeals can represent both a critical opportunity and a significant programme risk.

Why These Changes Matter for SME Developers

For SME developers, the planning appeal system is often a critical part of the development process.

Smaller developers frequently deliver schemes on sites that fall outside the focus of volume housebuilders, including infill plots, edge-of-settlement sites and smaller redevelopment opportunities. These projects can often attract cautious or inconsistent decision-making from local planning authorities, meaning that the ability to appeal is an important safeguard.

The procedural reforms coming into force in April 2026 do not remove that safeguard, but they do change how appeals will operate in practice.

Applications must be appeal ready from the outset

The most significant implication for SME developers is that applications must now be prepared as though they may be tested at appeal.

If an application is refused, there may be little opportunity to strengthen the evidence base afterwards.

All relevant information should therefore be submitted as part of the application, including:

• planning policy analysis
• technical reports addressing key constraints
• design justification
• transport and environmental evidence where relevant

Simply meeting a validation checklist will no longer be sufficient. Applications need to anticipate the likely planning concerns and address them upfront.

Pre-application engagement will become more valuable

Engaging with the local planning authority before submitting an application will become increasingly important.

Pre-application discussions can help identify the key issues that need to be addressed and establish agreement on the scope of supporting information.

Where the authority has not raised a particular issue during pre-application discussions, there may be stronger grounds for arguing that additional evidence should be accepted at appeal stage. However, this remains at the discretion of the Inspector.

Engagement during determination will be critical

Developers will also need to engage actively during the determination process.

Responding promptly to consultee comments and addressing emerging issues before a decision is made will be increasingly important. While it is still possible to amend proposals during the determination period, this flexibility does not extend to the appeal stage.

A Note of Caution on the Use of AI

There has been a noticeable increase in the use of artificial intelligence tools to generate planning statements and other supporting documents.

These tools can be useful in assisting with drafting and improving efficiency, and many consultancies now incorporate them within their workflows.

However, there are risks associated with relying on AI-generated material.

Under the new procedural framework it will be necessary to notify Inspectors where AI has been used in the preparation of submission documents. In addition, inaccuracies or unsupported statements produced by AI cannot easily be corrected during the appeal process if new evidence cannot be introduced.

For that reason, any use of AI should be carefully reviewed and supported by professional judgement and robust planning analysis.

Costs Risks

The reforms also reinforce the importance of the planning appeal costs regime.

Where appeals are pursued without adequate supporting evidence, or where arguments are poorly substantiated, Inspectors may award costs against appellants.

For SME developers operating within tight viability margins, avoiding unnecessary appeal costs will be essential.

Final Thoughts

The planning appeal reforms coming into effect in April 2026 are intended to speed up decision-making and reduce the administrative burden of appeals.

However, they also shift more responsibility onto applicants to ensure that planning applications are comprehensive and robust from the outset.

For SME developers in particular, the key message is straightforward.

Planning applications should now be prepared on the basis that the evidence submitted at application stage may ultimately form the entire foundation of an appeal case.

Those who approach the process strategically, ensuring applications are properly scoped and fully evidenced, will be best placed to navigate the new system.