What is a Habitats Regulations Assessment?

This article explains :

  • what a Habitats Regulations Assessment means
  • when it is needed
  • the three stages of the appropriate assessment process
  • possible mitigation measures

What does a Habitats Regulations Assessment (HRA) mean?

An HRA is a type of ecological survey which is required whenever a proposal is submitted concerning a piece of land within an impact risk zone where protected species are found. The HRA is a survey of wildlife in the area, examining how it might be affected by the proposed scheme to avoid the possibility of breaching EU legislation.

A competent authority, which may be a local planning authority, should assess a proposed development scheme in relation to the site’s conservation aims. It may grant approval only after having ruled out adverse effects on the site and where there are no alternative solutions; the plan can only proceed if there are overriding reasons of public interest and the necessary compensatory measures can be achieved.

A surveyor carrying out a Habitats Regulations Appraisal.

There is a legal obligation placed on competent authorities to consider the potential impacts of any development proposals which may have an adverse effect on land situated within a European designated site; this includes granting of planning consents and the HRA is the process by which this is assessed. European designated sites including Special Areas of Conservation (SAC), Ramsar sites and Special Protection Areas (SPA) are protected under the Conservation of Habitats and Species Regulations 2017 (as amended) and known as The Habitats Regulations.

Legislation is amended in The Conservation of Habitats and Species and Planning (Various Amendments) (England and Wales) Regulations 2018 to allow that where there is likely to be a significant effect on the environment, a competent authority may undertake an appropriate assessment to consider the impact and any mitigation measures before deciding on whether or not to approve the plan. This applies to neighbourhood plans, special development orders, local development orders, neighbourhood development orders, simplified planning zones and enterprise zones.

What triggers an HRA:

  • An application for development proposals, i.e., the prospect of increased pressure on an area of land.
  • The threat of disturbance to species or habitats.
  • Potential discharges into watercourses.
  • The prospect of noise, air or light pollution.
A great crested newt.

An HRA may involve up to 3 stages:

1. Screening:

A screening report must be carried out to find out whether a plan or project will have a significant effect on a site’s conservation elements. If the answer is no, there is no need to proceed to the second and third stages. A scheme’s design features including layout, may be considered by a competent authority at the screening stage, however, mitigation measures included to reduce the effects of a scheme on habitats cannot be taken into account at this stage of deciding whether an appropriate assessment is needed.

2. Appropriate Assessment:

Appropriate assessment must be made where the potential for having a significant effect on a site cannot be excluded. This stage of habitats regulations assesses the likely significant effects of the proposals on a protected site in detail and identifies ways of minimising these effects. A competent authority must consult the relevant Statutory Nature Conservation Body if it is in doubt, and they may make representations: in England this is Natural England, in Wales it is Natural Resources Wales.

The content of the appropriate assessment depends on the location, nature and scale of the plan and the individual features of the site. Assessment must be proportionate and sufficient to enable the competent authority to determine whether the plan will adversely affect the integrity of the site; it must contain complete findings to put the conclusion beyond reasonable scientific doubt. 

The applicant may be required to provide information for the assessment; all habitat types and species for which the site is protected must be catalogued. The regulations assessment must identify and examine the potential impacts of the plan on the designated features on site, including typical species of designated habitats and implications for habitat types and species outside the boundaries but likely to have contact with the site.

A local authority can only grant permission if it is satisfied that the consent includes conditions strict enough to guarantee that the development will not affect the site’s integrity: the ecological structure that enables it to support the habitat and species populations for which it was designated. If consent is granted and conditions are imposed to protect the site, the applicant may then proceed to details of the construction phase.

3. Derogation:

This stage is relevant when considering whether a plan or project that would have an adverse effect on a European site may qualify for an exemption. For this to apply, three legal tests must be passed:

◊ there are no feasible alternative solutions offering a less damaging option for the site.

◊ for overriding public interest reasons, the plan needs to proceed.

◊ the necessary compensatory measures can be secured to fully offset damage to the site.

What are mitigation measures?

These are imposed if there is no certainty that a scheme will not adversely affect a site’s integrity. It is important to note that compensation is not mitigation, and every effort should be made to avoid damaging a site’s integrity altogether; if this is not possible, impact reduction measures should be applied, such as a decision to implement the scheme at a less sensitive time of year, for example by avoiding the breeding season, choosing more environmentally-friendly construction methods, abandoning a part of the plan or opting for extra measures to reduce the scheme’s impact.

As mentioned above, a planning authority cannot consider any mitigation measures when it is making the screening decision over whether an appropriate assessment is required; mitigation can only be taken into account as part of an appropriate assessment itself.


Sites protected under the Habitats Regulations have stringent protections attached to them to ensure that they meet conservation objectives. The HRA is a rigorous process designed to protect vulnerable protected sites and species from being damaged or lost to development.

Do you need a Habitats Regulations Assessment?

Arbtech arbtech.co.uk are your best asset if you are considering a scheme which requires an HRA. Our expert consultants cover the whole of the UK and will be pleased to discuss your requirements with you.


GOV.UK. 2019. Appropriate assessment. [Online]. Available from: https://www.gov.uk/guidance/appropriate-assessment. (Accessed October 20th 2021)

GOV.UK. 2021. Habitats Regulations Assessments. [Online]. Available from: https://www.gov.uk/guidance/habitats-regulations-assessments-protecting-a-european-site. (Accessed October 20th 2021)

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