The developments listed in this guide are exempt from BNG rules.

Existing planning applications 

If a planning application for a development was made before day one of mandatory BNG on 12 February 2024, the development is exempt from BNG.

Variations of planning permission

Transitional arrangements also apply for variations to existing planning permissions. There is more information in the planning practice guidance.

Developments below the threshold

A development that does not impact a priority habitat and impacts less than:   

• 25 square metres (5m by 5m) of on-site habitat   
• 5 metres of on-site linear habitats such as hedgerows

A development ‘impacts’ a habitat if it decreases the biodiversity value.   

Find out more about this exemption.

Householder applications

These are applications made by householders as defined within article 2(1) of the Town and Country Planning (Development Management Procedure) (England) Order 2015.

It includes, for example, small projects like home extensions, conservatories or loft conversions.

Self-build and custom build applications

You must meet all of the following conditions to qualify for an exemption as a self-build or custom build.

The development must:  

• consist of no more than 9 dwellings 
• be on a site that has an area no larger than 0.5 hectares    
• consist exclusively of dwellings that are self-build or custom housebuilding as defined in section 1(A1) of the Self-build and Custom Housebuilding Act 2015

Find out more about what qualifies as self-build and custom housebuilding.

Biodiversity gain site

Developments undertaken mainly for the purpose of fulfilling the BNG planning condition for another development are exempt.

High speed rail transport network

An exemption applies to any 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.

Other exemptions

The following are exempt by the Environment Act 2021:

• urgent crown developments 
• developments that are granted planning permission by a development order (including permitted development rights)