Skip to content

Hertfordshire
search button
Hertfordshire County Council

Advice we give

Our ecology team offers specialist advice and guidance to Local Planning Authorities (LPA), organisations and individuals in Hertfordshire. We support a wide range of projects including household proposals and major schemes with:

  • local plans, planning documents and policies
  • planning applications that may affect protected species and habitats
  • biodiversity net gain.

More details on what we consult on

  • Desktop ecological assessments and data searches
  • Time planning around seasonal constraints
  • Various types of ecological surveys, including Preliminary Ecological Appraisal (PEA) and Phase 1 and 2 surveys
  • When an Environmental Impact Assessment (EIA) is required
  • Mitigation and enhancement opportunities
  • Pre-application and early-stage planning advice

 

Advice for householders

We've put together some guidance to help you prepare your planning application. The more information you include upfront, the less likely delays are to occur. 

When will I need to submit an ecological report as part of my planning application?

To provide us with the information we need, it is likely you will need to submit an ecological report with your application if any of the following conditions apply:

  • your application meets certain criteria in the local planning authority's (LPA) biodiversity checklist
  • there's a risk of the proposed development affecting protected species such as bats or great crested newts
  • your local planning authority has been advised by LEADS Ecology, or other informed consultees, that there is a risk of the proposed development harming biodiversity.

Applications that do not increase the footprint of a property


This section deals with applications that are limited to the demolition of, or modifications to, the property itself. 

For guidance on those applications that seek to increase the footprint of a property, either by means of extension to the property or the creation of a new structure separate from the property such as a separate garage, shed or summerhouse, see ‘Applications that increase the footprint of the property' below.

Houses of all styles, whether old or new, can support roosting bats and/or breeding birds. Though you may not be aware of them, birds can nest in lofts, gutters or gaps in the brickwork and bats can roost or shelter in the loft, beneath tiles and in the tiniest of gaps elsewhere. All are protected, most are in decline and all are especially vulnerable to householder applications for demolition, loft conversions and extensions amongst others. Indeed, although levels of protection vary, in general terms, as all bats and breeding birds, and their roosts and their nests are protected in law, it could be a criminal offence were you to harm these species.

The best way to find out if there is a reasonable risk of supporting bats is to complete your local authority’s ‘biodiversity checklist’. We strongly encourage all householders to add photographs of the property when submitting the checklist. See 'Can I submit photographs instead of commissioning a survey?' below. On receipt of this information your planning department and LEADS Ecology will determine the level of risk.

If the risk is low, there will be no need for bats to be considered further.  Where there is a risk, LEADS Ecology may recommend that a survey (or Preliminary Roost Assessment) is undertaken to check if there is any evidence that a roost may be present.  The reason for this is to make sure potential impacts are understood and allow measures to be adopted to reduce the risk of harm and of inadvertently committing an offence, and to enhance the value of the property for biodiversity. Such surveys can only be carried out by professional ecologists.

If the Preliminary Roost Assessment (PRA) finds the presence of a roost is unlikely, there is no reason for bats to be considered further. However, if a bat roost is found or there is reasonable potential for one to be present, up to three further ‘activity’ surveys at dusk may be required.

Whilst a PRA can be carried out at any time of the year, activity surveys can usually only be carried out when bats are active, typically between May and August, or September if the weather remains fine. Occasionally, if a winter hibernation roost is found or suspected, we may request a winter survey. Householders should bear in mind these potentially important seasonal constraints when planning their development.

If a bat roost is confirmed, mitigation measures will be required though most are relatively straightforward and typically include the careful destruction of the roost, and the installation of bat boxes to provide an alternative roost elsewhere in the roof, loft or walls of the property though occasionally it can be more complex.

In contrast, we rarely ask for breeding bird surveys, although a good Preliminary Roost Assessment should always identify if breeding birds are present though mitigation measures are usually more straightforward and typically comprise replacement nest boxes on, or around the property. This provides an opportunity to enhance biodiversity on your property by adding more boxes than necessary. 

Importantly, although many household improvements benefit from permitted development rights, this does not remove the need to take full account of potential impacts on biodiversity.

 

Bat surveys – further guidance on what to expect

Further guidance on what to expect from a bat survey can be found at the Bat Conservation Trust.

If a survey or report is needed, we strongly advise that you find a consultant by using the CIEEM directory.  Importantly, you should make sure they hold the appropriate licences from Natural England that allows them to both carry out surveys and undertake mitigation activities on bats and roosts. 

The Bat Conservation Trust provides further advice about finding an ecological consultant.

Applications that increase the footprint of a property

This section deals with applications that increase the footprint of a property, either by means of extension to the property or the creation of a new structure separate from the property including conservatories, garages, sheds and summerhouses. Those applications that do not propose an increase to the footprint of the property should refer to 'Applications that do not increase the footprint of a property‘ above.

Householder applications that increase the footprint of a property can involve the loss of all or part of an existing garden. Gardens can play an important role in supporting not only highly protected species such as badgers, bats, great crested newts and breeding birds but also more widespread species such as hedgehogs, frogs, toads and reptiles. The protection of all of these is important if we are to halt the decline in biodiversity across our county. Although levels of protection vary, it could be a criminal offence were you to harm bats, great crested newts, badgers or breeding birds amongst others.

Whilst in most cases LEADS Ecology will not recommend ecological surveys for gardens, there are some exceptions as follows:

  • where there are records of the presence of protected species such as badgers, great crested newts or reptiles such as slow worms within the garden or nearby
  • where trees are being removed that might provide roosts for bats.• Where the garden is part of a Local Wildlife Site
  • where the garden includes areas of ponds and orchards. 

 

The best way to find out if there is a reasonable risk of your garden supporting biodiversity is to complete your local authority’s ‘biodiversity checklist’.  We strongly encourage all householders to add photographs of the property when submitting the checklist. See ‘Can I submit photographs instead of commissioning a survey’ below. On receipt of this information your planning department and LEADS Ecology will determine the level of risk.

If we find the risk is low, there is no reason for the ecological impact of your proposal to be considered further.  If, on the other hand, the risk is high, LEADS Ecology may recommend that an appropriate survey is carried out or, for more substantial proposals, that a Preliminary Ecological Assessment is completed. These can only be carried out by professional ecologists.

The reason for this is to make sure potential impacts are understood and allow measures to be adopted to reduce the risk of harm and of inadvertently committing an offence, and to enhance the value of the property for wildlife. This will ensure your local planning authority has all the information on biodiversity it needs to make its decision.If important species or habitats are found, mitigation measures will be required though most are relatively straightforward and typically comprise making sure the work is carried out carefully though occasionally it can be more complex.

This usually arises where there is a reasonable risk bats, badgers or great crested newts might be present.  Where this occurs, it is likely, but not inevitable, that we will recommend that suitable surveys are carried out and the production of a report which will describe the mitigation required and any possible enhancements that could be delivered.

Importantly, although many household improvements benefit from permitted development rights, this does not remove the need to take full account of potential impacts on biodiversity.

 

Further guidance

If a survey or report is needed, it's important to choose an experienced ecologist to carry out ecology surveys and reports. They should have the right knowledge and licenses to both carry out surveys and undertake mitigation activities on great crested newts. You can find a list of trusted ecologist practices and consultants on the Chartered Institute of Ecology and Environmental Management (CIEEM) website.

Can I submit photographs instead of commissioning a survey?

Photographs cannot substitute for an ecological survey. However, they can help LEADS Ecology make a more informed ecological judgement as to the need for a survey. Therefore, we strongly encourage these are included with all householder applications.

Guidelines are included below as to the type of photographs that are most useful. If photographs are submitted, LEADS Ecology may still advise your local planning authority that an ecological survey is still required. 

Photographs are particularly useful for deciding if bats could be at risk. Therefore, if it is safe to do so, please provide photographs of the following (all photographs can be taken from ground level):

  • gable end edges, sufficient to reflect their overall nature and condition
  • bargeboards, fascias and soffits
  • external roof and tiles
  • internal loft spaces if accessible – to include roof lining, ridge, beams and floor / insulation.

If a garden (including a pond) is affected, please provide photographs of the entire area that will be affected. Without photographs it is more likely that a professional survey will be required in order to determine the presence of protected species which may be affected. 

 

Advice for ecological professionals

If reports are submitted that do not meet these standards, we reserve the right to advise the local planning authority that the report cannot be relied on.  This is likely to result in increased delays and All ecological assessments must reference and follow best practice guidance (ie CIEEM Guidelines for Preliminary Ecological Assessment Report (PEAR), Guidelines for Ecological Impact Assessment in the UK and Ireland (EcIA) and Guidelines for Ecological Report Writing).

  1. The title of the report should be either a PEAR or EcIA. (We acknowledge that a ‘full’ EcIA may not be proportionate for smaller developments but the principles must be followed with potential impacts fully explained and avoidance, mitigation, compensation and enhancement measures provided, for instance. Whilst we are content for consultants to make this decision, any deviation from the established approach must be explained. If your Preliminary Ecological Assessment Report (PEAR) concludes that your project will have negligible ecological impacts, no mitigation is required and no further surveys are necessary, you should submit the report along with your planning application.)
  2. Only EcIAs will be accepted in support of a planning application ; PEARs will not.
  3. Every PEA or EcIA must begin with a ‘Summary’ that clearly describes the main findings including a reference to this website to show it has been seen.
  4. All necessary surveys must be included and all must have been completed at a suitable time of year and if not, an explanation of this affects the outcome must be provided in the limitations section.
  5. To identify their importance, ‘higher value’ grasslands and woodlands affected by a proposed development must be compared with the site selection criteria for Local Wildlife Sites. (We are content for consultants to decide what constitutes a ‘higher value’ habitat but we will take a keen interest in site survey data to ensure this is applied reasonably).
  6. Every assessment should include a habitat map.
  7. Underpinning vegetation surveys should include quadrat data, which should correspond to the habitat map and the location of the quadrats shown.
  8. Photographs of key features should be included with at least one image of each described habitat type, either in appendix or main report.
  9. If reference is made to older surveys, perhaps by other consultancies, the results of these should be included in an annex, or the place to find them identified in the main text.
  10. The mitigation hierarchy must be followed with evidence to show how it has been put into practice and if not, why not.
  11. Every assessment must contain a discrete section entitled ‘Avoidance, Mitigation, Compensation and Enhancements’ which collates and clearly describes (eg the method, number, type and location of) those measures that are specific to the application; generic recommendations will not be considered appropriate.
  12. This section must also identify which measures have been incorporated in the submitted plans and which have not, and reasons provided for the latter.
  13. To reduce the need for conditions (and further consultations) consultants are expected to use reasonable endeavours to ensure all recommendations are adopted in the application and shown on appropriate plans; for example, all fixed structures, such as bat and bird boxes, must be shown on architectural drawings.
  14. In turn, these should tally with the Planning Statement and/or DAS where appropriate
  15. Each report must include a ‘limitations and restrictions’ section that clearly explains what factors may have affected the assessment and what measures or assumptions have been made to counter these.
  16. Ecological surveys and assessments should be carried out by qualified, suitable experienced ecologist using recognised methodology and at an appropriate time of year. All surveys must be compliant with best practice. The experience, qualifications (including licences held) and roles of all people who have contributed to the assessment must be detailed in any report.
  17. All relevant reports must be accompanied by an appropriate ecological records search from the Hertfordshire Environmental Records Centre (HERC).
  18. Only definitively stated mitigation, compensation and enhancement measures are acceptable.  

 

There is little here which isn’t already found in the aforementioned best practice guidance, but we have found following these simple rules will allow us to deal with your applications more rapidly. Importantly, these standards will be periodically updated and so frequent reference to this page is encouraged. 

 

Advice on Biodiversity Net Gain

The Biodiversity Metric

We will advise the LPAs that:

  • where applications have been submitted prior to the start date of mandatory net gain, we will advise that the BNG metric used should be either the most up to date version available at the time of application or if the applicant is seeking to demonstrate that it is compliant with current NE advise the statutory metric
  • in all other cases the Statutory metric should be used.

 

In all cases we will advise that:

  • the full original metric spreadsheet should be provided. A summary, pdf version or screenshot on its own is insufficient
  • the information required on the start page should be completed in full. 

Assessing Strategic Significance

The Local Nature Recovery Strategy (LNRS), expected to be completed in 2025, will identify areas for ecological improvement and outline the actions needed to deliver those improvements.

Until the LNRS is published, we will advise LPAs that the Herts Ecological Networks (HEN) Map (available from Herts Environmental Record Centre) should be used instead to assess strategic significance.

Herts Ecological Networks Map categories are as follows:

1 (green on the map) = Existing S41 NERC Act habitat.

2 (purple on the map) = Existing habitat not currently qualifying under S41 NERC Act. These include all known existing patches of habitats in a poor or degraded condition. They still have existing value, contributing to ecological networks, but are expected to require a degree of habitat restoration in order for them to maximise that contribution.

3a (orange on the map) = No mapped existing habitats present (high priority for habitat creation). These include all areas of the county where there are no mapped existing ecologically important habitats present and where it is predicted there will be the highest potential contribution to the restoration of ecological networks.

3b (yellow on the map) = No mapped existing habitats present (medium priority for habitat creation). These include all areas of the county where there are no mapped existing ecologically important habitats present and where it is predicted there will be medium potential contribution to the restoration of ecological networks.

3c (cream on the map) = No mapped existing habitats present (lower priority for habitat creation). These include all areas of the county where there are no mapped existing ecologically important habitats present and where it is predicted there will be a lower potential contribution to the restoration of ecological networks. 

Strategic significance should be assigned from the HEN as follows:


Strategic Significance within the MetricHerts Ecological Networks Map category

Within area formally identified in local strategy.

1, 2, (3a where area contains semi-natural habitat).

Location ecologically desirable but not in local strategy.

3b where area contains semi-natural habitat.

Area / compensation not in local strategy / no local strategy.

3c (3a and 3b where area does not contain semi-natural habitat).

 

Any variation from the above should be justified in the comment’s column of the metric. 

Metric Supporting information

In the absence of the following, Hertfordshire Ecology will not be able to advise the LPA that there is sufficient information for them to assess that the distinctiveness and condition of the habitats entered for metric calculations is accurate:

  • a survey methodology designed to assess the UK habitats present and their condition directly without the need for any further interpretation or use of correspondence tables. (See further advice on survey information)
  • expected standards of best practice can be found at Statutory biodiversity metric tools and guides (GOV.UK)
  • full quadrate and species lists – should be included in the appendix
  • condition sheets used to inform the metric
  • photographs: high quality images of quadrats to justify habitat identification and condition assessments will be required
  • habitat maps:
    • the location and size of each habitat parcel (pre and post development) must be clearly marked on maps
    • reference numbers for each habitat parcel to cross reference with the metric should be provided
    • the use of UK habitat symbology is required
    • competence: sufficient information to demonstrate the competence of all involved should be provided in line with the standards set out in BS8683. 

Biodiversity Opportunities and Local Wildlife Sites

We would look favourably on Biodiversity Net gain Schemes which incorporate, enhance, or make resilient local wildlife sites. So, any major developments where the red line boundary lies adjacent or very close proximity to a local wildlife site (LWS) will be encouraged to obtain either ownership or a long-term lease of the LWS to allow its management as part of the developments.

 

Advice on survey information

Ecological surveys

  • Surveys used to populate biodiversity metrics should be designed and carried out so that the UK habitat types present can be directly determined.  This will require use of quadrats. The use of other habitat classification systems that require translation via correspondence tables, other than for historic data sets, should not be used without consultation with the local planning authority.
  • To accurately describe UK habitat types a range of different measures such as % cover, abundance and species richness are often required. A simple measure of species richness alone is rarely sufficient. 

Grasslands

Grasslands are very vulnerable to loss by development and over 98% of Hertfordshire semi- natural grasslands have already been lost.  Where they are affected, particular care needs to be taken to correctly identify the grassland type so that suitable mitigation or compensation can be devised.

  • Surveys of existing grasslands should be carried out within the optimal survey period of mid-May to mid-August. Any surveys outside this period must be accompanied by compelling reasons as to why this is acceptable.
  • Survey area – small areas of similar stands of vegetation should be surveyed with a minimum of five quadrates or three if the area is very small but significant.  In larger homogeneous areas a minimum of ten quadrats should be used to ensure that at least 2% of the total area is surveyed in detail. The methodology should be fully described, and the location of all quadrats should be shown on the habitat map.
  • When assessing the grasslands, the information gathered should be sufficient to allow an assessment against the UK habitat descriptions for all grassland types. This should include as a minimum:
    a. Measures of abundance using the DAFOR scale of key grassland species identified in UK Habs, such as rye grass and false oat grass, as well as the overall abundance of grass species associated with intensive agricultural production.
    b. The abundance of indicator species of soil fertility.  
    c. % cover of grass species relative to forbes.  
    d. Overall % cover of key grass and ford species identified in UK Habs', such as rye grass and white clover. 
    e. Number of species per metre square. 
    f. Abundance of indicator species listed within UK habitat descriptions using the DAFOR scale.  
  • The absence of elements of this information can result in a lack of confidence in the assessed distinctiveness of the grassland and its base line value measured in the metric. This can result in us advising the LPA that further surveys are required resulting in potentially costly delays.

Woodland

The England Woodland Biodiversity Group (woodland condition methodology should be used for condition surveys, however, the appropriate statutory condition sheet should be completed for the assessment as this is adapted for use with the statutory metric. 

 

Raise an ecological objection or concern

There are various ways to report specific ecological issues or related concerns.

  • Report wildlife crime to Herts Constabulary
  • Report crimes against wild birds to RSPB
  • Report a distressed or abandoned animal to RSPCA
  • Objections to planning applications on ecological grounds should be reported to the relevant planning officer. All necessary details can be found on the council's planning portal.

Contact us

For specialist advice on a project or help with a planning application, you can get in touch with us.

 

Make a general enquiry

Rate this page

Happy face Neutral face Sad face