Biodiversity Net Gain Validation Requirements

Validation Requirements

Applicants must confirm whether they believe that planning permission, if granted, would be subject to the biodiversity gain condition, and if not, the reasons why. This is a new national mandatory validation requirement.

Where development would be subject to the general biodiversity gain condition, the application must be accompanied by minimum information set out in Article 7A of the Town and Country Planning Act 1990. For avoidance of doubt, the following is the mandatory minimum information required:

  • confirmation that the applicant believes that planning permission, if granted, would be subject to the biodiversity gain condition;
  • the pre-development biodiversity value(s), either on the date of application or earlier proposed date (as appropriate);
  • where the applicant proposes to use an earlier date, this proposed earlier date and the reasons for proposing that date;
  • the completed metric calculation tool showing the calculations of the pre-development biodiversity value of the onsite habitat on the date of application (or proposed earlier date) including the publication date of the biodiversity metric used to calculate that value;
  • a statement whether activities have been carried out prior to  the date of application (or earlier proposed date), that result in loss of onsite biodiversity value (‘degradation’), and where they have:
    • a statement to the effect that these activities have been carried out;
    • the date immediately before these activities were carried out;
    • the pre-development biodiversity value of the onsite habitat on this date;
    • the completed metric calculation tool showing the calculations, and
    • any available supporting evidence of this;
  • a description of any irreplaceable habitat (as set out in column 1 of the Schedule to the Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations [2024]) on the land to which the application relates, that exists on the date of application, (or an earlier date); and
  • plan(s), drawn to an identified scale and showing the direction of North, showing onsite habitat existing on the date of application (or earlier proposed date), including any irreplaceable habitat (if applicable).

In addition to these minimum requirements, further information may be required to assist the consideration of biodiversity net gain as part of the planning application, to enable the Local Planning Authority to consider whether the general condition is capable of being successfully discharged following approval. For example, where there are considerations around significant onsite biodiversity enhancements or use of offsite biodiversity units, a draft Habitat Management and Monitoring Plan (HMMP), completed draft metric demonstrating whether proposed net gain proposals are likely to be achievable, and details of all off-site habitats may be required. Specific further requirements will be set out in the Local Validation Checklist.

More information on Biodiversity net gain can be found in the planning practice guidance prepared by the Department for Levelling Up, Housing and Communities:
Biodiversity net gain