In general, exemptions from Biodiversity Net Gain are meant to be few and far between. Biodiversity Net Gain was introduced as a general condition for planning permission - as set out in the Environment Act 2021:
"grants of planning permission in England [are] to be subject to a condition to secure that the biodiversity gain objective is met"
As pointed out on BNG Online (a partnership between the Planning Advisory Service and the Future Homes Hub), "The list of exemptions from this requirement is narrow, focused and only open to certain types of application."
The following list of types of application are exempt:
Development granted planning permission by a development order under section 59.
Householder development. Development which is subject of a householder application as defined within Article 2(1) of the Town and Country Planning (Development Management Procedure) (England) Order 2015.
Temporary exemption for non-major development. This is open to non-major applications that were first submitted before 2 April 2024. To be eligible, the applicant should set out that the development does not meet the definition of major development set out under Article 2 Town and Country Planning (Development Management Procedure) (England) Order 2015. The exemption will continue to apply to section 73 permissions where the original permission which the section 73 relates to was subject to this temporary exemption.
De Minims Exemption. To be eligible, the applicant will need to demonstrate that the development that does not “impact” a priority habitat and “impacts” less than 25 square metres (e.g. 5m by 5m) of onsite habitat, or 5 metres of linear habitats such as hedgerows (note that “impact” is defined by The Biodiversity Gain Requirements (Exemptions) Regulations 2024). When providing reasons for the de minimis exemption, an applicant should provide sufficient evidence to support their justification. Where it cannot be clearly demonstrated through site plans and descriptions, applicants are strongly encouraged to provide a completed metric for the pre-development and post-development value for the onsite habitat and clear plans identifying the nature and size of this pre-development onsite habitat and how much of it will be impacted by the development (BNG PPF Paragraph: 004 Reference ID: 74-004-20240214). An example of the sort of application which would be eligible for a de minims exemption would be a minor extension to a visitor centre at a public nature park to accommodate a new accessible ramp and entrance lobby on an existing hardstanding area.
Self-build and custom build development. To be eligible, the development must:consist of no more than 9 dwellings, and be carried out on a site which has an area no larger than 0.5 hectares, and consist exclusively of dwellings which are self-build or custom housebuilding as defined in section 1(A1) of the Self-build and Custom Housebuilding Act 2015. It should also meet the definition set out in
Urgent Crown development granted permission under section 293A of the Town and Country Planning Act 1990.
Development of a biodiversity gain site. Development which is undertaken solely or mainly for the purpose of fulfilling, in whole or in part, the biodiversity gain condition which applies in relation to another development.
Development related to the high speed railway transport network. Development forming part of, or ancillary to, the high speed railway transport network comprising connections between all or any of the places or parts of the transport network specified in section 1(2) of the High Speed Rail (Preparation) Act 2013