BTF blog

Losing our Local Green Space designations

Are councils protecting our local green spaces? Our research reveals a worrying picture.

Parks, playing fields, village greens and community orchards are vital for our wellbeing — places where children play, neighbours meet, and nature finds a foothold in our towns and cities. Yet our research suggests that many local councils are failing to use the powers available to them to protect these spaces, leaving them vulnerable to development and neglect.

How we did our research

Using Freedom of Information laws, we contacted 62 Local Planning Authorities (LPAs) across England, asking whether their current local plan includes policies protecting Local Green Space (LGS) sites, as set out in the National Planning Policy Framework (NPPF). We also asked them whether any new local plan would do so.

The LGS designation was introduced in the NPPF in 2012 to give communities the power to protect the green areas that matter most to them. It remains part of national planning policy, and councils are expected to consider it when drawing up local plans.

Of the 62 requests sent, 55 councils have responded (88%). Eight told us they don’t hold this information. That left 47 substantive responses from councils with real power over local green space protection. Eight councils have yet to respond. The full collated responses are available online.

What we found: current local plans

Of the 47 councils that gave a substantive answer, 17 — 36% — confirmed that their current local plan includes LGS policies in line with the NPPF. Twenty-three said their current plan does not, mainly because it predates the NPPF (2012). Bromsgrove, Redditch and Stoke-on-Trent all have plans dating back to 2009/2011 and so that lack LGS provisions, though Stoke’s does contain general green space protections.

A further six councils gave qualified answers. South Hams, Stoke-on-Trent, Torbay and West Devon noted that designation of specific LGS sites has largely been left to Neighbourhood Plans. Solihull had adopted both an LGS policy and seven Neighbourhood Plans had also adopted their own LGS policies. This is a permitted approach, but one that places the burden on local communities rather than the council.

What we found: future local plans

The picture for future plans is only marginally better. Of the 47 substantive respondents, only 12 — 28% — gave an unqualified yes to designating LGS in their new or emerging local plan: Cheltenham, East Devon, Tewkesbury, Cannock Chase, Cotswold, Gloucester City, Bath and North East Somerset, Cornwall, North Somerset, Stratford-on-Avon, Swindon and Wyre Forest. Cotswold confirmed its 2025–43 plan will contain new LGS sites; Bath and North East Somerset (BaNES) proposes retaining and expanding its LGS policy, subject to Cabinet approval, and Stoke-on-Trent’s emerging plan contains LGS designations, a positive step for a city whose current plan predates the 2012 NPPF.

A further nine councils said they do not intend to designate LGS at all. Birmingham will continue using strategic, criteria-based policies rather than site-specific designations. Tamworth explicitly ruled out using LGS designations, citing limited space and preferring broader open space policies. Rugby says its emerging plan ‘defers to national planning policy’, and South Gloucestershire, despite having LGS policies in its current plan, will drop them from its new one. Broader open space policies offer some protection, but not the strong protection that LGS provides.

The largest group — 23 councils — said it was too early to tell or that no decision had been made, reflecting how slowly local plan preparation moves. Bournemouth, Christchurch and Poole, for instance, won’t be scoping consultation until June 2026.

Solihull is currently working on a new Local Plan, and will be reviewing the status of Local Green Space sites and whether there will be any amendments or additions to these.

The Bristol case: a warning from the front line

Bristol offers a stark illustration of what’s at stake. While our FOI research was under way, Bristol City Council, at the request of the examining inspectors, was removing all Local Green Space designations from its emerging local plan. Its current plan had included policy GI1, designating LGS sites identified through years of community consultation involving residents, community groups and the Bristol Parks Forum (BPF), with a matrix showing how each site met the NPPF criteria.

During examination, the inspectors rejected all proposed LGS designations as ‘not considered to be justified or effective,’ so the Council removed the policy entirely. BPF objects, pointing out that 14 sites met all five NPPF criteria and a further 27 met four, yet the Inspector rejected all designations en masse without considering the individual merits of each proposed site. BPF describe this as ‘a real disservice to the people of Bristol.’

The Council argues Bristol’s green spaces will still be protected through ‘Reserved Open Spaces’ (now call ‘Protected Open Space’ (POS)) status, but both we and BPF reject this as inadequate. POS does not carry the same weight or permanence as LGS. Other cited designations, such as Site of Nature Conservation Interest (SNCI) status, will offer weakened protection in the new proposed local plan. BPF cites Brislington Meadows as an example of a site that lost out despite its status as an SNCI. BPF says:

The only robust long-term protection for our locally important green spaces against development is to give a site Local Green Space designation. For a city like Bristol to have none is unbelievable.

Notably, Bristol’s FOI response makes no mention of this removal, instead stating that under the new system introduced by the new Levelling Up and Regeneration Act 2023 (LURA), it has ‘not yet decided’ whether its new local plan will designate LGS sites.

Both we and BPF are calling for the LGS policy and the proposed designations to be reinstated until a future local plan can provide equivalent or better protection, warning that any gap between local plans will leave green spaces exposed to development with no adequate defence.

LURA: a planning system in transition

Under LURA, there’s a transition deadline: plans submitted under the old system must be published by 31 December 2026. Authorities that fail to do this must use LURA’s streamlined 30-month timetable instead ­­— roughly half the current time required.

This is, in principle, an opportunity: many councils currently without LGS policies are operating under plans that predate the NPPF, and the obligation to produce a new plan forces the issue. But the compressed timetable, reduced consultation, and a shift of generic policies to national level all create conditions in which LGS designation could be marginalised or skipped. The Bristol example, where the Inspectors rejected all proposed LGS designations en masse, demonstrates this.

The role of Neighbourhood Plans

Local Green Space designation has often been left to Neighbourhood Plans rather than local plans. Bristol, Plymouth, Torridge, Torbay, Rugby, Solihull and Newcastle-under-Lyme all have made Neighbourhood Plans designating LGS, even where their local plan does not. These designations carry real weight, but Neighbourhood Plans require significant community time and resource. Relying on them risks a two-tier system where well-resourced communities can protect their green spaces but those with fewer resources cannot.

Why these issues matter

Bristol is a symptom of a wider problem. Access to good-quality green space improves mental and physical health, supports biodiversity, helps manage flood risk, and strengthens community cohesion. In cities like Bristol — which declared an Ecological Emergency in 2019 and is involved in nature recovery initiatives — densification without adequate green space protection directly contradicts those commitments. When councils fail to use the tools available, a community may find itself powerless to save a local green space, sometimes valued for generations, once a development application arrives.

What needs to change

Councils preparing new local plans should treat LGS designation as a core part of the process, not an optional extra, and should engage residents early on which spaces matter most. The Planning Inspectorate should also assess LGS proposals on their individual merits rather than rejecting them wholesale, as happened in Bristol. Councils currently reviewing plans that predate the NPPF have a clear opportunity to put this right.

What you can do

  • Get involved in your local plan consultation and make the case for LGS designation — and if your council is proposing to remove or weaken protections, say so clearly.
  • Ask your councillors whether your local plan protects local green spaces and what they’re doing about it.
  • Explore Neighbourhood Planning, which gives communities the power to designate LGS directly and may, in some cases, come with government funding.
  • Engage with council open-space strategies and green infrastructure reviews to help build the evidence base for future designations.
  • Support your local parks forum: organisations like the Bristol Parks Forum hold councils to account and amplify community voices. If your area doesn’t have one, consider helping to start one.

The places where we walk, play, breathe and connect with each other and with nature are worth fighting for — but only if we use the planning system’s tools, hold councils to account, and make sure that our communities are genuinely heard.

Speaking up for Bristol

The last opportunity for us to comment on Bristol’s proposed local plan has now passed, so all we can now do is hope that the Inspectors change their minds and reverse their decision to revoke all proposed LGS designations.

In any event, the Council assures us that it will publish its timetable for a further new local plan, as required under the new LURCA regime, by the end of June. When it does, we must insist that it reinstates its original ambition to adopt an LGS policy and designate LGS sites.

A copy of this article is available here: Losing our Local Green Space designation – 16 June 2026

Here are Bristol Parks Forum’s representations: Bristol Parks Forum response to Bristol Local Plan EXA064: Schedule of main modifications 11 June 2026

Cotham School and the Stoke Lodge trees

In its Information Statement of October 2025 concerning its recent fencing works at Stoke Lodge Playing Fields, Cotham School has chosen to misunderstand our concerns about the welfare of the trees at Stoke Lodge Playing Fields.

The Information Statement includes the following:

‘In planning the work to reinstate the fence, the School wanted to respond to feedback, to improve safety by removing muddy paths, to respond to the Bristol Tree Forum concerns regarding footpaths impacting on the roots of trees protected by Tree Preservation Orders, to reduce any other ecological impact and to create an enhanced local open space.’

Our complaints about the detrimental impact caused by the school’s original fencing layout on all the trees – not just the trees protected by Tree Preservation Orders (TPOs) – growing around the boundary of the site and on the playing fields were made in February 2020, nearly six years ago, in this blog: The trees at Stoke Lodge Park and Playing Fields – a letter to the Council. Cotham School has ignored these complaints and has never approached us to discuss our concerns.

Furthermore, Cotham School’s decision to drive its new fencing through the root zones of several TPO trees, one of which is a veteran boundary oak, and to destroy other trees, some of which are protected by a TPO, makes it clear to us that the school continues to ignore the welfare of the trees growing at Stoke Lodge.

We have reported these most recent breaches of TPO legislation to the Local Planning Authority. We have also made clear to Bristol City Council our concerns about the welfare of the Stoke Lodge trees generally. We have been ignored.

As a result of this neglect, the long-term welfare of all the trees growing on and around the playing fields is at risk.

Assessing habitat parcels: strategic significance explained

To calculate the biodiversity value of a habitat, it’s important to assess its strategic significance. A habitat’s strategic significance takes into account both its type and its location. If strategic significance is high, then the habitat’s value will be uplifted by 15%. However, as this article explains, the opportunities for doing this are limited.

A habitat parcel is an area of habitat which is all of the same distinctiveness, condition and strategic significance. Strategic significance refers to the importance of a habitat parcel based on its location and type.

Each habitat parcel needs to be assessed both before, when the baseline habitat is surveyed, and after development, on or off site.

This flowchart sets out how to assess the strategic significance of a habitat parcel. It uses the tables, shown below, from the Statutory Biodiversity Metric User Guide.

Our blog, The Local Nature Recovery Strategy fails to deliver for Bristol assesses the implications of this for Bristol, which recently adopted the WECA LNRS.

These are the tables referred to in the flowchart:

Table 7: strategic significance categories where an LNRS has been published.

Table 8: strategic significance categories where an LNRS has not yet been published.

Replacing lost biodiversity: a missed opportunity for local offsetting?

When developers cannot meet their obligation to replace habitat lost within their development site, plus at least 10%, they may buy habitat units to offset this lost habitat. These habitat units are available in ‘biodiversity gain sites’.

This article was updated on 23 February 2025 to take account of the development of our new site which dynamically analyses the Biodiversity Gain Register and collates and summarises the published data:

The BGS Register

To date, 46 of these biodiversity gain sites (BGS) have been registered in England. They provide:

  • 1,376.7 hectares (ha) of baseline area habitat.
  • 32.76 kilometres (km) of baseline hedgerow habitat.
  • 11.37 km of baseline watercourse habitat.

The BGS sites cover 1,770.41 ha, though not all of this area is used for habitat improvement. 1,420.83 ha baseline habitats are made available for offsetting habitat loss caused by development elsewhere where this lost habitat cannot be replaced on the development site itself.

Distribution of biodiversity gain sites in England

19 of the 46 BGS sites are controlled by  RSK Biocensus Limited as the Responsible Body but are mostly owned by Environment Bank. One other is controlled by  Harry Ferguson Holdings (based on the Isle of Wight) as the Responsible Body, with the remaining sites under the control of various Local Planning Authorities (LPA) as the Responsible Body. We assume that the LPA sites have been created in order to deal with those local developments which require offsite mitigation. Nonetheless, these sites are also selling habitat to developers which require offsite mitigation but are outside the LPA boundary.

We also ask who is policing these sites to ensure that was has bee promised is being delivered? This must especially be the case for LPA sites given that the LPA cannot monitor itself?

In Bristol the LPA has delegated this function to neighbouring authorities using s.101 Local Government Act 1972 (the power for councils to delegate functions to other local authorities). – See 30 Sept 2024 Economy and Skills Committee notes – from paragraph 9. It will be interesting to see how this turns out. However, despite this, no BGS sites have yet been registered in the city, so it is hard to see how this initiative will be delivered where offsite mitigation is required.

The habitat improvement potential

These sites provide a total of 4,819.3 area baseline habitat units (HUs), 325.59 hedgerow baseline HUs and 105.6 watercourse HUs – we have assumed that all the sites have low strategic significance and that the watercourse habitats are free of encroachment.

We have been able to calculate the improved habitat units being created but not the improved habitat units being enhanced. This is because the parameters upon which these baseline habitats are being improved have not been identified.

The take up to date

So far, 31 of these 46 BGS sites have been used by 59 LPAs to allocate lost habitat caused by 85 developments. The majority of habitats are Other neutral grassland and the remainder are Lowland meadows, Traditional orchards, Floodplain wetland mosaic and CFGM, Mixed scrub, Woodland and forest and Hedgerow habitat.

To encourage developers to choose sites as close as possible to the habitat loss, they don’t need to pay a ‘spatial risk’ penalty if the biodiversity gain site is within the same Local Planning Authority (LPA) as the development. However, if the biodiversity gain site is outside the LPA for a particular development, the developer must pay a penalty when calculating the number of habitat units to be offset. If the site is in an adjacent LPA, the penalty is 25%. If it is farther away, the penalty is 50%.

Unfortunately, it appears that developers are not using BGS within their LPA areas (if available) for offsetting but are paying the spatial risk premium, though perhaps this is because they have no choice as there are no local BGS sites available.

Our analysis shows that, to date, the average distance between the centre of the LPA* where the habitat was lost and where its loss is offset is 80.1 km, with the greatest distance between loss and replacement being 344.8 km. Only six sites are within 10 km of the site of the habitat loss, while 23 are over 100 km away.

* It is difficult automatically to calculate the exact site of the habitat loss on the basis of the information provided. If at least Post Codes were provided, this would be possible.

What is particularly notable is that many of the development sites we have examined appear to be in locations where there should be ample opportunities for local habitat to be improved, but nothing has been done to realise this. Even the South Downs National Park LPA has allowed the replacement of habitat lost in two applications on the same site under its care near Petersfield to be exported to a site some 67 km away near Lewes, albeit that it is still in the National Park.

Furthermore, all 46 of the BGS sites are located on private land, in rural settings that are not easily accessible, whereas the lost habitats were largely located in built-up areas.

However, given the requirement that offsite mitigation only be delivered on registered sites, its hard to see what choice developers have apart from testing the BGS market and buying the cheapest habitats required, albeit that this may be miles from the site of the original loss.

This is still a small sample, which will grow over time so, perhaps this will change as more biodiversity gain sites become available and a clearer trend emerges. At the moment, however, the trend is not encouraging and looks like it will result in local nature, especially in urban settings, becoming hollowed out, as we feared it would when the biodiversity net gain requirements became obligatory nearly a year ago. See our article on this: ‘It seems inevitable Bristol will see a steady, inexorable biodiversity decline’

The Local Nature Recovery Strategy fails to deliver for Bristol

WEMCA’s Local Nature Recovery Strategy (LNRS) will fail to provide Bristol with the benefits promised for nature. While the new Biodiversity Net Gain (BNG) rules require most development in the city to increase biodiversity by at least 10%, unfortunately the LNRS will not apply to most potential development sites.

The West of England Mayoral Combined Authority (WECA as was) Local Nature Recovery Strategy was published to much fanfare last November. Defra’s blog, Kickstarting local nature recovery: a new strategy for the West of England, hailed it as the first in the country.

The LNRS is a locally led and evidence-based strategy which aims to target action and nature investment where it’s most needed. We’re told that the strategy will also focus on biodiversity net gain by increasing the strategic significance of specific habitats. However, it is hard to imagine how the LNRS will help to enhance biodiversity net gain in most, if not all, potential development sites in the city.

We might have been better off, at least as far as the application of biodiversity net gain to new development is concerned, by asking the LPA to specify alternative documents (such as those listed at the end of this article) for assigning strategic significance instead.

The issue

When calculating the impact of a proposed development on biodiversity, one factor taken into account is the strategic significance of any habitat found on a focus area for nature recovery site (coloured purple in the map above). If strategically significant habitats are created or enhanced, then their strategic significance is set to High in the Statutory Metric calculator tool and a 15% uplift to the calculation of its value is applied. Subject to which of the six LNRS areas is being considered, these are the strategically significant habitats in the city:

  • Ditches
  • Ecologically valuable lines of trees
  • Ecologically valuable lines of trees – associated with bank or ditch
  • Grassland – Floodplain wetland mosaic and CFGM
  • Grassland – Lowland calcareous grassland
  • Grassland – Lowland meadows
  • Heathland and shrub – Mixed scrub
  • Heathland and shrub – Willow scrub
  • Individual urban or rural trees
  • Lakes – Ponds (priority habitat)
  • Priority habitat (on the River Avon and the Riparian buffers)
  • Species-rich native hedgerow with trees – associated with bank or ditch
  • Species-rich native hedgerow with trees
  • Species-rich native hedgerows – associated with bank or ditch
  • Species-rich native hedgerows
  • Urban – Open mosaic habitats on previously developed land
  • Urban – Biodiverse green roofs
  • Woodland and forest – Lowland beech and yew woodland
  • Woodland and forest – Lowland mixed deciduous woodland
  • Woodland and forest – Other woodland; broadleaved
  • Woodland and forest – Wood-pasture and parkland

However, a detailed examination of the LNRS map reveals that not all parks and green spaces have been designated as focus area for nature recovery sites. It’s only those which are in one or both of the following:

  • a location where they can make a greater contribution to ecological networks
  • deprived areas with a lack of access to nature.

These designations were based on Bristol’s previous work on ecological networks within the city and where wildlife-friendly interventions are most likely to be feasible. This means that the existence, creation or enhancement of these special habitats outside these areas will not attract the 15% strategic significance uplift.

The BNG requirements

The now compulsory Statutory Metric Guide, used for calculating Biodiversity Net Gain (BNG), advises (at page 27) that: ‘Strategic significance is the local significance of the habitat based on its location and habitat type. You should assess each individual habitat parcel, both at baseline and at post-intervention, for on-site and off-site.’

If the LPA has adopted an LNRS then only the High or Low strategic significance multipliers can be used (High – formally identified in local strategy = 1.15. Low – area compensation not in local strategy = 1). If it has not adopted an LNRS, then the Medium strategic significance multiplier may also be used (Location ecologically desirable but not in local strategy = 1.10).

Where an LPA has adopted an LNRS, all those sites which have not been identified as a focus area for nature recovery site will be designated as having Low strategic significance and so attract no uplift, even if they’ve been identified as important habitats in the Local Plan or in another strategic document adopted by the Council. These documents (used where an LPA has not adopted an LNRS) can include:

  • Draft Local Nature Recovery Strategies
  • Local Plans and Neighbourhood Plans
  • Local Planning Authority Local Ecological Networks
  • Parks and Green Spaces Strategies
  • Tree and Woodland Strategies
  • Area of Outstanding Natural Beauty Management Plans
  • Biodiversity Action Plans
  • Species conservation and protected sites strategies
  • Green Infrastructure Strategies
  • River Basin Management Plans
  • Catchment Plans and Catchment Planning Systems
  • Shoreline management plans
  • Estuary Strategies

Baseline habitats cannot be uplifted

Despite the BNG strategic significance guidance, Defra has stated that LNRS designations only apply to the creation or enhancement of post-development biodiversity mitigation habitats. They don’t apply if these habitats – called the baseline habitats – are found on the site before development begins.

This means that the 15% strategic significance uplift can only be applied where offsite biodiversity mitigation is being delivered in a focus area for nature recovery site. If these habitats are being delivered elsewhere, the uplift may not be applied.

However, even if the baseline habitats were included, it is unlikely to make any difference This is because the focus area for nature recovery sites identified in Bristol are, for the most part, located in public parks or green spaces, on river banks, in riparian buffers or on railway margins, none of which are likely ever to be developed or, in many cases, used to offset habitat lost to development elsewhere.

So far, no announcement has been made as to whether any of Bristol’s focus area for nature recovery sites will be made available for offsite habitat mitigation and the proposed new Local Plan does not commit to using these sites for this purpose.

This, combined with the challenge of finding LNRS suitable for offsite habitat mitigation, registering them as biodiversity gain sites and then managing them, effectively, in perpetuity, suggests that few feasible LNRS sites will be found, especially as many sites are also in demand for public access for recreation.

We set out the process used to assess the strategic significance of habitats on our blog, Assessing habitat parcels: strategic significance explained.

The 2025 Annual Tree Giveaway – free saplings available for planting

Many thanks for of of you who have asked for trees – over 1,200!

We have now closed the offer.

Planting a tree is, perhaps, one of the most significant things we can do to help protect our future environment, promote nature and make the world a better place for the generations to come. The trees we plant today will continue to provide benefits for the environment, wildlife and people, for hundreds of years.

A veteran chestnut

We all know the value of trees in sequestering carbon, and they still represent the most effective and widespread means of removing CO2 from the atmosphere. For instance, a single mature oak tree is the equivalent of 18 tonnes of CO2 or 16 passenger return transatlantic flights. However, it is in our cities that trees provide the greatest benefits; cleaning our air, reducing flooding, improving our physical and mental health, and, crucially, reducing temperatures during heat waves.

Our cities suffer additional problems during heat waves, with all of the concrete and tarmac absorbing a lot of energy from the cooling sun and releasing it as heat. This “heat island” effect can raise temperatures by as much as an additional 12 degree centigrade. Trees can greatly reduce, or even eliminate, this effect, partly through shade but also actively cooling the air by drawing up water from deep underground, which evaporates from the leaves… a process called evapotranspiration. According to the US Department of Agriculture, this cooling effect is the equivalent to 10 room sized air con units for each mature tree. This cooling greatly enhances our resilience to the dangerous heat waves that are predicted to increase in severity and frequency.

A veteran Beech

A stand of Silver birch

Also, Trees improve air quality by absorbing both gaseous (e.g., NO2) and particulate pollution. They reduce traffic noise and flooding and improve physical and mental wellbeing.

Thus, trees are a crucial, but often ignored, element in increasing our resilience to climate change.

What are the Bristol Tree Forum doing to help?

It is said that the best time to plant a tree is 20 years ago, and the second-best time is now.

Unfortunately, important mature trees are constantly being lost to development, damage and disease. Though these might easily be replaced by new trees, what is less easy is replacing the decades or even centuries that the tree has taken to grow, the carbon that the tree has sequestered, the ecosystems the tree supports and all of the other benefits trees provide. For these reasons, most of the work of the Bristol Tree Forum focuses on protecting our existing trees. These efforts are particularly crucial in the urban environment where our trees are under the greatest threat.

However, as well as advocating the retention of life-saving trees in our city, Bristol Tree Forum have been encouraging new tree planting by holding an annual tree giveaway since 2020; the ancient trees of the future are being planted today! Most of Bristol’s trees are sited in private land and gardens, so the trees we have are mostly thanks to the efforts of Bristol residents, and it is those residents we must look to if we want to increase our tree canopy.

Over the last four years, we have given away around 10,600 trees, with species as diverse as English and Sessile oak, Downy birch, Silver birch, Grey birch, Alder, Alder buckthorn, Rowan, Scots pine, Sweet chestnut, Sycamore, Spindle, Wild cherry, apple, pear and plum.

The trees planted to date.

Trees given away in 2022 / 2023

Red oak sapling

This year’s Tree Giveaway has been made possible by the generous support of Maelor Forest Nurseries, based on the Welsh borders, and Protect Earth whose aim is to plant, and help people plant, as many trees as possible in the UK to help mitigate the climate crisis.

Thanks to Maelor, we are able to offer a variety of species with a wide range of sizes and preferred habitats, including Pedunculate (English) oak, Red oak, Sweet chestnut, Silver birch, Sycamore, Hawthorn, Beech, Hornbeam, Wild cherry, Alder, Red alder, Field maple and Norway maple.

Trees can be ordered using the form below

We will get delivery of trees in February, when the trees can be collected from a site in Redland, Bristol. We will email you when they are ready.

The saplings come bare-rooted (i.e. out of the soil) and will need to be planted as soon as possible after collection, although the viability of the trees over winter can be extended by storing the trees with the roots covered in damp soil.

The form below is to find out who would like to have saplings for planting, which species, how many and where you plan to plant them.

Please provide your email so we can contact you organise collection of the trees. Your contact details will be kept private and will not be used for any other purpose than to process your request.

Our Giveaway offer has now been filled.

Thanks for all your support.

Biodiversity gain: will urban nature become hollowed out?

In a boost for the environment, new legislation now obliges most developers to set out how they will achieve at least 10% more biodiversity than already exists on their proposed development sites.

Developers must now show how they will improve the biodiversity of their development site as a result of their works. Developers must record the (baseline) on-site habitats that exist before development starts and show how they will either enhance or replace these on site. If their proposals fail to reach the 10% threshold, the developer may provide the shortfall elsewhere. This post-development mitigation should be done as closely as possible to the development site, or at least within the Local Authority. However, if this isn’t possible, they can use approved sites anywhere in England.

This approach is called the Biodiversity Gain Hierarchy (found in Schedule 7A of the Town and Country Planning Act 1990 at section 37A). The Hierarchy says it’s a priority to avoid the ‘adverse effects’ to ‘onsite habitat with a habitat distinctiveness score … equal to or higher than four.’ If this can’t be avoided, only then is mitigation permitted. In our experience, nearly all developers ignore the requirement to avoid adverse effects and move straight on to mitigation.

Since the introduction of the Bristol Tree Replacement Standard in 2013, developers (and planners) have ignored the policy requirement to avoid tree removal where at all possible. Instead, they’ve moved straight on to providing compensation for the trees lost to the development. As a result, the money set aside for replacement tree planting was not spent (on occasion reaching nearly £1 million) and many of the lost trees were never replaced.

Under the Hierarchy, habitats that score four are designated as having medium distinctiveness. While many habitats have medium distinctiveness, many don’t. For example, managed grassed areas (called ‘modified grassland’) are often found on urban sites but have a low distinctiveness score. So, too, do many other urban habitats such as allotments and gardens. Developers are not required to avoid harming these, though losses to these habitats must still be mitigated.

There’s no definition of what an ‘adverse effect’ is or any guidance on how it is assessed. However, recent advice from the Bristol’s Chief Planner about the meaning of ‘harm’ suggests that this could be interpreted very broadly or simply ignored because some sort of mitigation will always be available.

In the last extreme, developers may purchase biodiversity credits. We wait to see how this and the offsite biodiversity mitigation market evolves, but a 2012 paper published in the Harvard Environmental Law Review suggests that such environmental markets are prisoners of their own geography because the space available is always constrained:

Markets for water quality, biodiversity, endangered species, fisheries, air quality, and aquatic resources, to name a few, must recognize that the commodities they trade exist at particular geographic scales, and set appropriate spatial limits on the redistribution of environmental quality. The size of geographic trading areas has significant implications for the economic viability of markets and the ecological quality of their offsets.

This will be a particular challenge when providing biodiversity mitigation in urban areas.

The squeeze on green spaces

Land use in Bristol is subject to intense competition by many stakeholders. This is especially true for our green and open spaces, which offer many ‘services’ beyond just habitat provision. There is very little, if any, space available for new biodiversity to be created. At best, some green spaces might be enhanced, but opportunities to do this are likely to be very limited.

For example, Bristol Tree Forum’s examination of the three proposals to develop Bedminster Green shows that, if these proposals are allowed, then nearly 400 new trees will need to be planted to compensate for the lost tree habitat – a medium distinctiveness habitat. There’s no room to plant these trees on site, so offsite provision will be needed. There are very few opportunities for doing any new tree planting (as opposed to replacing lost trees) in the surrounding wards or even across Bristol, let alone, as is usually required, within a mile of a development site.

Instead, these replacement trees will have to be planted somewhere else: ‘in some foreign field that is forever Bristol’. This will inevitably lead to a net loss of biodiversity across the city as nature is ‘hollowed out’. This is unacceptable. The whole purpose of the new biodiversity gain regime is to improve overall local biodiversity, but it seems inevitable that Bristol will instead see a steady, inexorable decline.

We are disappointed that the current draft of the new Local Plan addresses none of these issues and have said so in our responses to the latest consultation:

Bristol Tree Forum representations in relation to the Bristol Local Plan 2023 Publication Version consultation & BTF Representations on the Bristol Local Plan 2023 publication version – Addendum.

A shorter version of this article was published by 24/7 as:

‘It seems inevitable Bristol will see a steady, inexorable biodiversity decline’

Why Bristol needs a Biodiversity Net Gain SPD

The new Biodiversity Net Gain (BNG) obligations, which came into force last February, aim to improve our natural environment by requiring that all new developments have a positive impact (a net gain of at least 10%) on biodiversity.

For this reason, we believe that Bristol urgently needs to follow the lead of the other west of England councils, B&NES, South Gloucestershire and North Somerset, and adopt a Biodiversity Net Gain Supplementary Planning Document (SPD). A list of other local authorities that have adopted their own biodiversity SPDs can be seen here on the Local Government Association planning advisory service website – Biodiversity Net Gain in Local Plans and Strategic Planning.

Councils are encouraged to develop a locally specific SPD as part of their Local Plan. This would:

  • set out local priorities and strategies that require developers to deliver BNG locally
  • ensure that BNG contributes to wider nature recovery plans such as the newly launched Local Nature Recovery Strategy (LNRS) and other local objectives, and help ensure that the right habitats are provided in the right places
  • link BNG requirements to other strategic objectives and place-making policies in the Local Plan, to ensure a more holistic approach
  • set requirements for managing and maintaining habitats provided through development.

Having such a document would clarify exactly what developers need to do in terms of the BNG requirements. While these requirements have many gaps, they are now, as it were, the only game in town and we must try to make the best of them. We believe that developing a robust BNG SPD could help mitigate these problems by adding tougher conditions that developers must meet.

With the launch of the LNRS – a collaborative effort to help people and organisations within WECA and North Somerset take effective action for nature – it has become more important than ever for Bristol City Council to bring this strategy into action, especially where new development is planned.

Two factors causing us the most concern (there are others) are the exclusion of stakeholders from the BNG decision process and the lack of enforcement of BNG requirements.

Consulting stakeholders

We’ve long been concerned that the new BNG regime excludes stakeholder groups such as ours from engaging with and commenting on the approval process for Biodiversity Gain Plans (BGPs) because of the way the planning rules work.

The BGPs are a post-approval requirement (see Schedule 7A of the TCPA ’90, Part 2, section 13(1)), which means there’s no obligation for a developer to demonstrate how it will meet its BNG responsibilities during the application stage (although the Council could require this).

Under current rules, BGPs only need to be submitted for approval to the Planning Authority after an application has been approved. However, there’s no statutory requirement to consult any statutory bodies on BGPs or to publicise or consult on the submission of a BGP prior to its approval. It seems, therefore, that we (and other stakeholders who, like us, are fighting for everyday nature) will have no say in what is proposed, or even have any idea of what a BGP contains or how it could affect us.

Surely this goes against the principles of open governance and localism which councillors should be fighting to defend, especially where it’s likely to have a direct impact on the very places that we Bristolians love and value?

Improving enforcement

As a recent article in Local Government Lawyer magazine points out, there are serious issues around BNG enforcement that need to be resolved.

We’ve been trying to engage with council officers over this issue for some time, but so far without success. Maybe the time has come for the Council to seize the initiative? With the proposed new Local Plan moving towards its public hearings stage early next year and the likelihood that the plan will be adopted next April, maybe now is the time for the reconstituted Local Plan Working Group to take this in hand.

This is what the Council currently requires from developers: Biodiversity Net Gain for major development and small site planning applications. At best, this is only advisory, unlike an SPD which would be part of the Local Plan and so compel the developer’s compliance.

One of our fears is that some planning conditions, such as this one from the recent, pre 12 February 2024, Bristol Rovers Memorial Grounds application are unenforceable. In this case they only oblige the club to submit a proposed Landscape Ecological Management Plan (LEMP). They did this last June. However, the wording of the condition means that the club is not obliged to perfect this or even to carry it out.

Readers may recall that the development had been completed and the new stands occupied long before the main application was made, well before this and other conditions had been submitted or approved. In addition, as part of the eventual approval, the club agreed to plant a wood on a piece of unused land it owns to the south of the new stadium (the area shaded green below), but this has not yet been done.

As part of this agreement, the club is expected to enter into a LEMP to plant the wood and then maintain it in perpetuity. The LEMP Condition says:

Within 6 months of the date of consent, the applicant shall submit a 30-year Landscape and Ecological Management Plan (LEMP). This should address retained features of ecological interest, together with mitigation and enhancements to be provided. The LEMP should set out management compartments, objectives, and prescriptions for all new proposed soft landscaping/planting to demonstrate how all habitats will be managed to their target condition (as specified in the BNGA). It should also show how management of the site will be resourced and monitored.

In this example, all that can be enforced is a failure to submit the LEMP within six months, which, in this case, has been done. There is a S106 imposing LEMP obligations but this is toothless and, anyway, only the Council can enforce it – which it is not obliged to do.

There’s also the practical effect of the Biodiversity Gain Hierarchy – Biodiversity net gain Guidance Paragraph: 008 Reference ID: 74-008-20240214. This effectively means that the developer need not achieve any net gain on site, or even locally, but can instead deliver it anywhere in England or, as a last resort, simply buy BNG credits, though at a premium.

For example, the grant conditions – 11 (The BGP condition), 12 & 14 – in the recent, post-12 February Council application, The White Hall, Glencoyne Square, are unenforceable given their wording as there is only an obligation to submit; again, approval is not required. We assume that a s106 agreement and a Habitat Management and Monitoring Policy (HMMP) will need to be produced, but, at the moment, we still have no idea how the self-acknowledged 38.09% habitat loss will be mitigated, or where.

Given the intense competition for space in the city, it seems inevitable that, as a result of the application of the Biodiversity Gain Hierarchy, Bristol’s nature will, bit by bit, be exported to some far-off field that no one knows or cares about. In theory, a BNG SPD could at least try to ensure that habitats lost to development are replaced locally wherever possible.

It’s been suggested that new SPDs can’t be delivered until after the new Local Plan has been examined and formally adopted. Maybe, but we see no reason why we can’t at least start a conversation about this. As it is, the proposed Local Plan will need substantial redrafting to align with the new BNG rules, having been adopted by the Council before these had been finalised.

It’s also been suggested that there are neither the funds nor enough officer time available to develop this new SPD. However, since all the adjacent councils (members of WECA), and many farther afield, have developed, or are developing, their own SPDs, we can surely save time and expense by looking on these as templates from which to build our own. The examples above alone make it all the more urgent for issues such as this to be resolved with the early adoption of a BNG SPD. We urge the Council to commission officers to draft an SPD as a matter of urgency.

A shorter version of this blog was published in 24/7 as: ‘Without enforcement, Bristol’s nature will be exported bit-by-bit‘

How to assess the condition of a tree

There are special rules for assessing the condition of Individual trees habitat, as set out in the biodiversity gain guidance.

The criteria set out in the  Statutory biodiversity metric condition assessments table must be used to decide on the condition of Individual trees habitat, which is scored as follows:

ConditionScore
Good3
Moderate2
Poor1

There are six criteria for assessing a tree’s condition. If a tree passes five or six of the criteria, it is in good condition. If it passes three or four of the criteria, it is in moderate condition. If it passes two or fewer of the criteria, it is in poor condition.

These are the six criteria to consider:

A – The tree is a native species (or at least 70% of the block are native species).
B – The tree canopy is predominantly continuous, with gaps in canopy cover making up <10% of total area and no individual gap being >5 m wide (individual trees automatically pass this criterion).
C – The tree is mature (or more than 50% of the block are mature).
D – There is little or no evidence of an adverse impact on tree health by human activities (such as vandalism, herbicide or detrimental agricultural activity). And there is no current regular pruning regime, so the trees retain >75% of expected canopy for their age range and height.
E – Natural ecological niches for vertebrates and invertebrates are present, such as deadwood, cavities, ivy and loose bark.
F – More than 20% of the tree canopy area is oversailing vegetation beneath.

The ‘Fairly Good’ and ‘Fairly Poor’ condition categories are not available for this habitat type.

Enhancement of this habitat is only possible by improving it so that it meets the criteria B, D and F. It is not possible or appropriate to enhance individual tree/s through meeting just one or two of these criteria, nor by meeting only A or C or E.

It is important that the species of each tree on site is properly listed by the developer. Here is the list of the native species defined by the Statutory Metric:

BNG – valuing habitats

With the introduction of the Biodiversity Metric, all existing (i.e. baseline) habitat parcels on proposed development sites are given a calculated habitat value, called Habitat Units (HUs).

Baseline habitat parcels

Baseline habitat is the habitat that exists before a site is developed. Development sites often contain a mosaic of baseline habitats each of whose condition may vary. These are called habitat parcels.

The area of a habitat parcel is measured in hectares (or square metres when using the Small Sites Metric). Linear habitats parcels are measured in kilometres (or metres when using the Small Sites Metric).

The sum of all the ground-based area habitat parcels should equal the area of the proposed development site (the redline boundary).

Calculating HUs

The HU calculation uses the following formula:

HU = Habitat area/length x Distinctiveness x Condition x Strategic Significance.

The Distinctiveness of each habitat is predefined. These are the Distinctiveness scores:

Very High8
High6
Medium4
Low2
Very Low (hedgerow module)1
Very Low (area module) 0

The Condition of a habitat is assessed using the various matrices set out in Statutory biodiversity metric condition assessments published by Defra. These are the scores:

Good3
Fairly Good2.5
Moderate2
Fairly Poor1.5
Poor1
Condition Assessment N/A 1
N/A – Other0

The Strategic significance of a habitat is its importance according to its location and habitat type. Each of these elements is given a score which is then used in the HU formula. These are the scores:

High1.15
Medium1.1
Low1

For example, an area habitat parcel covering a hectare, which is of medium distinctiveness, in moderate condition and of medium strategic significance, is calculated as follows:

1 ha (area) x 4 (distinctiveness) x 2 (condition) x 1.1 (strategic significance) = 8.8 HUs.

Individual trees habitat

There is a special formula for individual trees habitats. This is because they oversail the habitat on the ground and so are non- ground-based habitats, which need to be treated differently from ground-based habitats.

This table shows the four size classes for Individual trees habitats:

It uses the diameter at breast height (DBH measured 1.5 metres above the ground) of each tree growing on a proposed development site (if the tree is multi-stemmed, the largest DBH recorded is used) and assigns a ‘Biodiversity metric area equivalent’ to calculate its habitat area. This value represents canopy biomass, and is based on (but not the same as) the root protection area formula, derived from BS 5837:2012. 

For example, a medium-size individual trees habitat covers an area of 0.0163 ha and has medium Distinctiveness. If it is in moderate Condition and of medium Strategic significance the HU value is calculated as follows:

0.0163 ha (area) x 4 (distinctiveness) x 2 (condition) x 1.1 (strategic significance) = 0.14344 HUs.

Post-development habitat creation and enhancement

The biodiversity metric also applies three additional risk factors to all post-development enhanced and created habitat parcels, across all three habitat types – Area, Hedgerow and Watercourse – using this formula: 

HU = Habitat area/length x Distinctiveness x Condition x Strategic Significance x Temporal Risk x Difficulty factor x Spatial Risk

Temporal risk

This represents the average time lag between the start of habitat parcel creation or enhancement works and the target outcome date. This is known as the ‘time-to-target condition’ and is measured in years.

If there is a delay in creating or enhancing the habitat parcel, or it has already been enhanced or created, this can be factored in to adjust the time-to-target period either up or down.

The temporal risk period is automatically applied by the biodiversity metric and changes depending on target habitat condition. As a result, the temporal risk multiplier, based on the 3.5% discount table below, sets the current value of the future habitat being created.

Difficulty of creation or enhancement

The creation and enhancement categories represent the uncertainty of the effectiveness of techniques to create or enhance habitat parcels. 

The biodiversity metric automatically assigns the delivery risk and score for each habitat parcel, based on its habitat intervention category. 

CategoryValue
Low1
Medium0.67
High0.33
Very High0.1

Spatial risk

Where a project cannot achieve a net gain in biodiversity units on site, then offsite HUs can be used to meet the BNG requirement.

The spatial risk penalty (SRM) reflects the relationship between the location of on-site biodiversity loss and the location of off-site habitat compensation. It affects the number of biodiversity units provided to a project by penalising proposals where off-site habitat is located at a distance from the development site.

  • If the offsite area is within Local Planning Authority (LPA) boundary or National Character Area (NCA), the penalty is x 1.0.
  • If it is in a neighbouring LPA or NCA, the penalty is x 0.75.
  • If it is elsewhere (anywhere in England), the penalty is x 0.5.

The effect of this is that it costs more HUs to achieve the BNG requirement the farther away the offsite mitigation is from the location of on-site biodiversity loss.

Post-development Individual trees habitat creation

When creating Individual trees habitat, post-development size class of a tree is determined by its size when it is planted. Newly planted trees should be recorded as small-sized, unless the tree is actually medium-sized or above at the time of planting.

In our experience, nearly all nursery-grown trees are small-sized, as this table, derived from BS 3936-1, demonstrates.

For example, a small-sized tree covers an area of 0.0041 ha and has medium Distinctiveness. The difficulty of creation factor is preset at Low.

If it is planned for it to achieve a moderate Condition, the time-to-target period will be 27 years. If it is planted within the LPA in an area of medium Strategic significance, its HU value will be calculated as follows:

0.0041 ha (area) x 4 (distinctiveness) x 2 (condition) x 1.1 (strategic significance) x 0.382 (temporal risk) x 1 (difficult factor) x 1 (spatial risk) = 0.01378 HUs.

Other Blogs in the series

Tree Habitat Area Calculation

The Trading Rules Explained