The Department for Infrastructure issued a new Development Management Practice Note 9a (DMPN 9a) ‘Unauthorised Environmental Impact Assessment (EIA) Development’ in December 2021.

Whilst the guidance confirms that unauthorised EIA development can be regularised and approved – and indeed the statutory framework allows for this – the bar for approval is significantly higher.

The fundamental purpose of EIA is to identify the likely significant effects of a development and thus the DMPN 9a aims to guide planning authorities through the requirements of EIA when a development either does not have the required planning permission or has been carried out without compliance with conditions.

The DMPN 9a only deals with EIA and not other environmental regulations such as Habitat Regulations Assessments pursuant to the Conservation (Natural Habitats etc) Regulations (Northern Ireland) 1995 which should also be borne in mind by planning authorities and developers alike when considering retrospective planning applications.

This legal insight will focus primarily on the legal principles surrounding retrospective EIA and the implications.


The Planning Act (NI) 2011[1] is the starting point for the legislative regime for planning control and enforcement in NI and any reference to ‘unauthorised development’ in DMPN 9a is to development carried out in breach of planning control.

EIA is governed by the Planning (Environmental Impact Assessment) Regulations (Northern Ireland) 2017 which sets out that planning authorities are prohibited from granting planning permission or subsequent consent for “EIA development” unless an EIA has been carried out.

This involves 1) a screening process (determining whether EIA is mandatory or required with reference to relevant thresholds and likely impacts). And 2) a scoping process (determining which environmental factors must be included in the Environmental Statement if one is required).

The preparation of an Environmental Statement is costly and time-consuming, particularly when combined with the fees required for submission to the relevant planning authority. However unauthorised EIA development is not an attractive alternative given the range of enforcement powers available to planning authorities (and obvious potential risk to the environment).

Enforcement powers

Section 4 of DMPN 9a reiterates the enforcement powers available to planning authorities under the 2011 Act namely:

  • the issue of a planning contravention notice (section 133);
  • the issue of an enforcement notice (section 138);
  • the issue of a temporary stop notice (section 135);
  • the issue of a stop notice (section 150);
  • the service of a breach of condition notice (section 152); and
  • an application to the court for an injunction (section 156).

When an enforcement notice in relation to unauthorised EIA development is appealed, the Planning Appeals Commission (PAC) must not grant planning permission on any part of that development until an EIA has been carried out. In practice, the PAC will often schedule an appeal for an EIA determination first before proceeding to hear a separate deemed planning appeal for the unauthorised development. This gives the appellant an opportunity to be heard independently on the need for an Environmental Statement first.

Stop notices and injunctions are used to a lesser extent and only when the risk of environmental harm is so high that it is expedient for a planning authority to use such powers. DMPN 9a provides guidance to enable more effective responses by planning authorities to unauthorised EIA development so perhaps in the coming months we will see more reasoned decisions in relation to enforcement action.

Legal principles

Section 5 of the DMPN 9a emphasises that the ‘precautionary principle’ should be applied when a planning authority is undertaking a screening determination of whether an unauthorised development is EIA development.

The Northern Ireland Court of Appeal has recently reaffirmed the precautionary principle. It was held in Re Friends of the Earth Ltd's Application [2017] NICA 41 that the precautionary principle applies and operates on the basis that there should be no planning permission granted unless and until it is established that there was no unacceptable impact on the environment.

In practical planning terms, the emphasis on the precautionary principle is likely to result in more positive EIA determinations if planning officers have any reasonable degree of uncertainty as to whether the unauthorised development has or will have likely significant environmental effects.

That said, the DMPN 9a encourages planning authorities to set out clear reasons in their screening determination which are to be backed up by evidence. Lack of reasoning is one of the key grounds of attack in many judicial reviews in this jurisdiction so better reasoning should lead to more certainty in the EIA process.

Case law also confirms that retrospective planning permission can be lawfully granted for an unauthorised EIA development. However, there is a potential sting in the tail; even where an EIA is submitted, and the proposal is acceptable in principle in both planning and environmental terms, approval is far from the given outcome. DMPN 9a reiterates the principles set out in the case of R (Ardagh Glass Ltd) v Chester City Council [2010] EWCA Civ 172 and, subsequently, R (Padden) v Maidstone Borough Council [2014] EWHC 51 (Admin) which are worth summarising:

A. The decision-maker has discretion to justify the grant of retrospective consent only in “exceptional circumstances”;

B. The decision-maker should consider whether granting permission would give the developer an advantage they ought not to have due to the breach of planning;

C. The public, and other stakeholders, should be provided  with equal opportunity to advance their views on the application and its Environmental Statement;

 D. The Environmental Statement and the EIA must be  rigorously scoped to ensure its assessment is based on a reasonable estimation of the baseline environment that is likely to have existed on the site prior to the unauthorised EIA development having taking place.

From a practical perspective a retrospective baseline may be difficult to assess since details of the pre-development baseline may not be readily apparent. However, provided the baseline is “reasonable” and sensible conclusions can be reached, this in many cases is less of a problematic hurdle.

A substantially higher bar to surmount is the consideration of “exceptional circumstances” and “unfair advantage”. These, inevitably, will be very case-specific, but give planning authorities (whether a council, the PAC or the Department for Infrastructure) very wide discretion over what those terms mean. The DMPN emphasises that this is a “very high bar”.

Further, where approval is granted, the DMPN notes that the authority must “publicly record the reasons and justification that enabled it to confirm that all of the above principles had been satisfied”. Retrospective EIA development can often be controversial. Failure to give adequate reasons is a common ground of challenge in judicial review proceedings and so planning authorities must give careful consideration to reasons given. Equally the same approach must be given to a refusal, since the developer may seek costs on appeal or recourse to the High Court where reasons are insubstantial or flawed.

The DMPN does not introduce any new concepts or requirements, since the principles it sets out have been in play at least since the Ardagh Glass decision in 2010. However, what it does provide are very clear and potentially stark directions on the circumstances where unauthorised EIA development can be acceptable. Whilst the ability to gain retrospective permission is enshrined in the planning legislation, where EIA is also required, the scope for approval may be substantially constrained even if a development is otherwise acceptable in principle.

DMPN 9a can be viewed at: Development Management Practice Note 9a: Unauthorised Environmental Impact Assessment (EIA) Development (

[1] The Department for Infrastructure is currently undertaking a review of the implementation of the Planning Act (NI) 2011 following a Call for Evidence in 2021 -Call for Evidence - Review of the Implementation of the Planning Act (NI) 2011 - TLT LLP (

This publication is intended for general guidance and represents our understanding of the relevant law and practice as at February 2022. Specific advice should be sought for specific cases. For more information see our terms & conditions.

Written by

Sarah Mulholland

Sarah Mulholland

Date published

04 February 2022



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