What are the exemptions?
The exemptions to the mandatory requirement were set out in the government response to the BNG regulations and policy consultation. The exemptions legislation was laid before parliament on 19 January and will become law when BNG goes live on 12 February.
The list of exemptions from the BNG requirement is narrow and focused, keeping the policy ambitious, whilst being proportionate and deliverable for developers and local planning authorities:
Development below a de minimis threshold
This exemption applies to development that does not impact a priority habitat and impacts less than 25 square metres (e.g. 5m x 5m) of non-priority onsite habitat (such as modified grassland) or 5m for non-priority onsite linear habitats (such as native hedgerows). This exemption is designed to ensure that BNG does not apply to either very small scale development or development which does not impact habitat, through loss or degradation within the red line boundary. In practice, this will be demonstrated by a decrease in the biodiversity value, which is determined by the biodiversity metric.
If a development impacts less than 25 square meters of non-priority habitat but 5m or more of non-priority linear habitat is negatively impacted, or vice-versa, then the exemption will not apply and all habitats will be subject to BNG.
If any priority habitat within the red line boundary of the development is impacted, the exemption will not apply and all habitats will be subject to BNG.
Developers should consult publicly available data sets on priority habitats to check whether there is priority habitat on site, they do not need to seek specialist advice to record the presence of priority habitat.
An example of 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. This proposal would not negatively impact or alter any habitat, but the red line which defines the development is likely to contain more than 25sqm of non-priority habitat.
It’s worth remembering that existing sealed surfaces such as tarmac or buildings are assigned a zero score in the statutory biodiversity metric, meaning that these surfaces are effectively exempted from the 10% net gain requirement.
This exemption ensures that BNG is applied proportionately and that a development does not incur unnecessary extra cost to, for example, comply with accessibility requirements as in the example above. It also encourages developers to design in ways to avoid impacting the habitat on site in the first place, following the biodiversity gain hierarchy.
Further information on this exemption, including what evidence will be required to show that a development is in scope of this exemption, is available in the planning practice guidance.
Householder Development
This exemption applies to development to an existing house (including development within the curtilage of a house.) An example of this type of development is adding a side-return.
It does not cover applications for change of use of a house or to change the number of dwellings in a building.
Biodiversity Gain Sites
Where an off-site biodiversity gain project itself requires planning permission, the enhancement may require its own 10% net gain. This would then effectively decrease the biodiversity gains created. This exemption will prevent that. This applies to:
- developments which solely enhance biodiversity to achieve the BNG planning condition for another development through off site enhancements of habitat.
- development undertaken to fulfil the BNG planning condition and for the purpose of permitting the public to access or to use the site for educational or recreational purposes without the payment of a fee.
Small Scale Self-Build and Custom Housebuilding
To support smaller developers, we are exempting small scale self and custom build development from the BNG requirement. This exemption applies only to development that:
- consists of no more than 9 dwellings;
- is carried out on a site which has an area no larger than 0.5 hectares; and
- consists 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. This definition covers development where local planning authorities are satisfied that individuals have had the primary input into the final design and layout of a house to be occupied as homes for themselves.
This size criteria will ensure that only small self and custom build sites are caught by the exemption. Self and custom build sites in excess of these thresholds, which are impacting more habitat and so have more scope to deliver gains for nature will to be required to deliver a net gain. This will apply whether they are a standalone development site or secured for self or custom build as part of a major development.
High Speed Railway Transport Network – The exemption for the High Speed Railway Transport Network covers development which is part of or ancillary to the remaining phases of the high speed transport network.
26 comments
Comment by Anna Spencer posted on
My local planning officer is applying BNG to my gravel driveway going across my garden lawn to my house (and only my house)
Total madness
Comment by jessicaeverett posted on
Hi Anna, thanks for your comment and sorry to hear of your frustration.
We can’t comment on specific cases, but it’s worth saying that individual Local Planning Authorities might have requirements in addition to Defra’s policy. Our BNG exemptions represent the minimum requirements.
Best wishes,
Jess (Blog team)
Comment by Derren posted on
Is the change of use that's been over 10yrs exempt from BNG?
It's been stone/gravel for about 15yrs.
Kind regards
Comment by jessicaeverett posted on
Hello Derren,
Thanks for your question. This is a tricky one for us to answer, because we can't comment on individual case. Specific Local Planning Authorities might have requirements in addition to Defra’s policy, so it's probably best to contact yours for an answer.
Best wishes,
Jess (Blog team)
Comment by Marilyn Cox posted on
Please define side-return as stated
Comment by jessicaeverett posted on
Hi Marilyn,
Thanks for your question. A side-return, or side-return extension to give the full term, is where a house is extended into the narrow strip of land or pathway alongside the house.
Remember, Local Planning Authorities (LPAs) might have requirements in addition to Defra’s policy. So it is worth double-checking with your LPA what their requirements are.
Thanks,
Jess (The Blog Team)
Comment by Qwaz posted on
This sounds like a right load of smoke and mirrors!
Haven't seen any real useful responses either
Comment by jessicaeverett posted on
Hello,
I'm afraid we are limited in what we can say in response to questions about specific locations/developments, just because of the local authorities setting their own criteria (potentially over and above the baseline government requirements).
But I'm very happy to find answers to any wider policy questions you might have about BNG - do please just response to this comment.
Thank you,
Jess (The Blog Team)
Comment by Andrew Jeffrey posted on
Does the BNG exemption re size apply to the whole size of the land registry plot or can an applicant sneak into the exemption category by just building on a site of under .5 hectares on part of the whole site?
This applicant is claiming exemption from BNG for a self build of three houses on a site of under .5 hectares. However, the whole land registry plot size is greater than one hectare.
Comment by jessicaeverett posted on
Hello Andrew,
I spoke to the BNG team. They said that BNG applies to all habitats within the red line boundary of a development. In order to qualify for the self and custom-build exemption, the development must meet all three of the criteria which are that 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
More detail on the guidance page: https://www.gov.uk/guidance/biodiversity-net-gain-exempt-developments
Hope that helps.
Thanks,
Jess (The Blog Team)
Comment by Andrew Jeffrey posted on
Hi Jess,
Thank you for your reply. The question in this case is whether that is the red line boundary on the land registry title plan or is it the arbitrary boundary on part of the land which has been parcelled up for three self build houses on part of the title which is less than .5 hectares.
Surely a developer can’t simply parcel up and salami slice small sections of the whole title so as to avoid BNG legislation? This would mean developers could develop small parcels at a time to get round the rules.
Comment by jessicaeverett posted on
Hi Andrew,
Thanks for your patience with our response time. I’ve discussed with the team (who also spoke to colleagues at MHCLG), and the question of where to draw a red line boundary isn’t a new BNG issue – it’s just managed through the planning process as normal.
Overall planning application guidance is clear that the entire application site should be edged clearly with a red line on the location plan. It should include all land necessary to carry out the proposed development (for example, land required for access to the site from a public highway, visibility splays, landscaping, car parking and open areas around buildings).
In most cases the curtilage of the development will have an obvious boundary.
As part of the planning process, Local Planning Authorities check that all land necessary has indeed been included in the red line boundary. For some more complex developments, the Local Planning Authority will need to discuss these cases individually with the applicant.
Here’s the link to the guidance I mentioned: https://www.gov.uk/guidance/making-an-application
Hope that helps.
Thanks,
Jess
Comment by Adam posted on
Hi,
Curious on the Small Scale Self-Build and Custom Housebuilding exemption. Would this still apply if there is a priority habitat within the redline?
Thanks
Comment by jessicaeverett posted on
Hi Adam,
Thanks for your question.
There is no priority habitat condition as part of the self and custom build exemption, but existing planning policy to protect and enhance priority habits applies to all planning applications.
The National Planning Policy Framework states this explicitly. To get a bit technical, the mitigation hierarchy in paragraph 186 (a) states that a planning application should be refused if significant harm to biodiversity resulting from the development cannot be avoided (through locating on an alternative site with less harmful impacts), adequately mitigated, or, as a last resort, compensated for.
Thanks,
Jess
(The Blog Team)
Comment by Gavin Garmston RIBA posted on
Hi,
I believe a project I have submitted to HCC LPA is exempt from needing a BNG assessment. The project is to convert an existing outbuilding into a dwelling. The curtilage is a 100% concrete yard. The only construction outside of the footprint of the existing structure is a 7m² access ramp for wheelchair access which is replacing concrete. The planner seems confused about the requirements but is refusing to back down and is now suggesting that plant growth in the cracks of the old concrete is a habitat that needs assessing despite the fact that the client could rightly and lawfully clear his driveway of unwanted growth any time he wishes. I don't know who to turn to without incurring ecologist fees to simply confirm that the project is exempt.
Comment by jessicaeverett posted on
Hello Gavin,
Thank you for your comment. I'm sorry, but we're not able to discuss individual applications. This is because LPAs might have requirements over and above those of Defra.
I'm sorry not to be more help.
Best wishes,
Jess
(The Blog Team)
Comment by Gavin Garmston RIBA posted on
I'm not really sure what the point of this blog is then.
Your reply could apply to literally any question posted on here. Architects like myself have taken time to learn the new regulations, support the principals behind it, but receive no support when we're faced with undertrained planning officers that are happy to halt local development due to their lack of understanding. I find the approach of introducing legislation, then adopting the "nothing to do with us guv!" position you've taken to be one that will cause more harm than help to the environment as you're seeding mistrust, frustration and justifying developers' tendencies to skirt the rules when they can. You have the luxury that it's the architects that have to bear the brunt from both sides due to no fault of our own. We're off to a very poor start in my opinion.
You could have also answered the question within the context of the DEFRA rules and regulations. A simple caveat saying the LPA could ask for more wouldn't be too complicated for me to understand. The case officer is misquoting the DEFRA regulations, not alluding to additional LPA rules, so I believe you are in a position to clarify the DEFRA standpoint on the scenario described.
Comment by jessicaeverett posted on
I appreciate it's frustrating. We're happy to answer questions about the wider BNG policy and direct to guidance where needed, but just can't comment on individual applications.
Thanks,
Jess
Comment by Gavin Garmston RIBA posted on
Thank you for your second reply. I would normally have stopped the conversation at this point, but I literally have no one to turn to except an ecologist who will charge my client £1200 to tell the planner what I've already told them.
Hypothetically: A project is converting an existing structure into a dwelling. To the the front of the structure is a 100% concrete yard. A large buddleja plant has taken root in a crack in the concrete and has grown (for arguments sake) to cast a shadow on the ground that is more than 25m², but has a trunk of 30cm². Under the DEFRA understanding of the rules only... Is that buddleja exempt from requiring an assessment? Y/N?
Comment by jessicaeverett posted on
Hi again Gavin,
Firstly, I should apologise – I was rushing when I responded before, and only saw the first 2 sentences of your previous comment. I didn’t realise there was more to it than what was showing on my preview screen, sorry.
I’ve spoken to the team, and the most we can do is reiterate the guidance around the de minimis. So if the habitat within the red line boundary isn’t a priority habitat, and if there’s less than 25m2 of habitat with a biodiversity value (i.e. not hard standing) within the red line boundary being impacted by the works being carried out, the development can be exempt under the de minimis.
But, not wishing to sound like a broken record, LPAs may have their own BNG requirements on top of this (though I do appreciate you’re saying this might not be the case in your particular instance).
To support LPAs in the implementation of this policy, we have provided them with funding for staff training on BNG and to support with extra staffing requirements.
We have also sent your example to the Planning Advisory Service. Although they are not able to respond to individual planning queries, they are working with LPAs to provide them with BNG training and guidance.
Best wishes,
Jess
Comment by Gavin Garmston RIBA posted on
Thank you Jess. I appreciate your time on this.
Comment by DR DAVID G. HEMINGWAY posted on
Hi Gavin
Buddleja is considered an invasive species and can be a serious problem to the built environment. Ideally it should be listed on Schedule 9 of the WCA.
Remove it and explain why - it has no ecological value in the wider countryside NOT ALLOWING IT TO SPREAD SHOULD BE MANDATORY REQUIREMENT. Contact Natural England and get a supporting statement to include with the PA.
Best wishes
DR DAVE HEMINGWAY Senior Consultant Ecologist
Comment by Caroline posted on
Do you need BNG for a small solar array of 24 panels that don't sit on the ground but on legs and the habitat beneath is muddy pioneer habitat and will not be taken away but improved. This is for householder to power their own home. These will be on their own property and already have a track leading to them as they have other solar panels that were erected in 2021. They just require the extra to make their home and annexe cottage self sufficient all year?
Thanks
Comment by jessicaeverett posted on
Hi Caroline,
I'm afraid we can't comment on individual planning questions. This is because LPAs might have their own requirements above and beyond Defra's.
However, you may find it useful to read the Defra guidance or the Planning Practice Guidance, which include more detailed information on when the de minimis exemption may apply. If you search for 'BNG de minimis' online you'll be able to find those documents. If you get stuck, let me know and I'll email you the links.
Thanks,
Jess (The Blog Team)
Comment by Roger posted on
I recognise that you are not able to comment on individual applications so I just want to make some general points about the BNG process from a layperson's point of view.
My family own a small plot of land (around 0.5 Ha). It is in the middle of a small village and would be in a superb situation for development of two reasonable size houses. This development is supported by neighbours.
My brother went into a care home a few years ago and to help pay for his fees it would be very beneficial if we could get planning permission for the land. In order to do this we got in touch with a land development consultant a couple of years ago who has been handling the process for us.
Earlier this year the agent informed us that we would not be able to apply for planning permission without getting BNG assessments completed. He has seemed quite confused about the process throughout the year and to date we have paid thousands of pounds for a string of assessments including a reptile survey, survey of hedgerows, survey of habitat units etc. The reports that we have received have been obscure and written in a way that neither we (or our agent) fully understand and that have proved fairly useless in deciding what we need to do next. The professionals who have done the assessments keep changing their minds about the number of habitat and hedgerow units that need to be compensated for and keep pressing on us that we need more and more assessments. As someone who is fairly naive in these matters, it just seems that the environmental assessors have no great interest in producing a practical solution but seem to be more concerned with maintaining a steady stream of income from a situation where they hold a high degree of power and influence.
In our most recent communication from our consultant he stated that his reading of the situation is that we will need to pay in the region of £70k-£100k to buy the necessary BNG compensations. Having seen the site and its few patches of brambley scrub this seems barely believable but, of course, we have no way to question assessments that have been undertaken.
As the compensation that we will need to pay for the BNGs will swallow up a large proportion of any profit we may make from selling the site my family are on the verge of giving up and possibly using the land for agricultural or other purposes.
As someone who has been involved in environmental issues in the past I am very supportive of governmental initiatives to maintain environmental sustainability. However, I feel that the current process is so uncertain and opaque that I wonder how much positive environmental effect it will actually have.
There are three main questions / issues I would like to raise:
1) The Labour Government has committed to building 1.5 million new homes during the course of this parliament. If other small landowners are experiencing the same level of stress and difficulty in the first steps of trying to develop small parcels of land (that would be ideal for new homes) surely this makes the whole commitment look increasingly unlikely? Under the previous government far fewer homes were built than were needed. Unfortunately it looks like the changes in the planning processes over the last year mean that (unless something radical is done) the process of building new homes will slow even further.
2) Environmental Assessment companies and assessors now have a very high level of power in that, without their assessments the whole planning progress grinds to a halt. What oversight and regulation do these companies / assessors have to ensure that they maintain consistent standards, reasonable pricing structures etc?
3) As a previous commentator on this blog has noted, it appears that the current system is punishing people who are trying to follow the (unclear) rules and it would seem to encourage unscrupulous developers to skirt the rules whenever they can.
I'm sorry for the negative tone of these comments but my family and I are feeling very frustrated that we have spent so much money and time over the last year and seem further away from getting a resolution than ever!
Comment by jessicaeverett posted on
Hello Roger,
Sorry for the delay in coming back to you.
Thank you very much for your detailed comment – I shared it with the team.
As you acknowledge, we can’t comment on specific applications, but they did suggest you might want to check if your development counts as a small site.
Developers of small sites, which includes developments of up to 9 houses on a site of up to 0.5ha, can choose to streamline the BNG process by using the small sites metric. That metric can be completed by a competent person rather than a qualified ecologist.
To support ecologists working on BNG, Natural England is supporting the development and delivery of metric trainings, including via the Chartered Institute of Ecology and Environmental Management. Defra is also working with the British Standards Institute to produce new principles for nature markets and a process for accreditation against those standards.
On your point about planning processes - Britain is facing both a housing and a nature crisis. The new Planning and Infrastructure Bill will reform the rules that are blocking economic growth and slowing down new homes and infrastructure, while helping to reverse nature’s decline.
The bill will require developers to pay into a nature restoration fund that will pay for large-scale environmental improvements to nature, water and air quality. This approach will restore nature, habitats and species across entire communities.
For some reason I can never get links to work well in comments, so I’ll include some relevant ones below. You might need to copy and paste them into your browser.
• https://www.gov.uk/guidance/understanding-biodiversity-net-gain
• https://www.gov.uk/guidance/biodiversity-metric-calculate-the-biodiversity-net-gain-of-a-project-or-development
• https://www.gov.uk/government/publications/planning-reform-working-paper-development-and-nature-recovery/planning-reform-working-paper-development-and-nature-recovery
Thanks,
Jess