NatureScot pre-application guidance for solar farms

Version: February 2025

This latest version of our guidance replaces a previous version published in August 2022.  It includes new advice on visualisation-related material, updated advice on peatland and biodiversity enhancement, as well as more general changes to align with National Planning Framework 4 (NPF4) policy and details on the new InformedDECISION platform for consulting us. 

Purpose

This guidance presents our standing pre-application advice on natural heritage considerations for applications and Environmental Impact Assessment (EIA) reports for large-scale, commercial solar photovoltaic (PV) proposals. 

The guidance is aimed at a range of people involved in preparing and reviewing planning applications for example, developers, consultants and consenting authorities. 

It outlines the survey and assessment work that is likely to be required to support an application but should be read in conjunction with any planning authority guidance on solar energy development.

The service that NatureScot provides

Our pre-application engagement provides an opportunity to resolve potential problems early on and help speed up decision-making. Our Service Statement and related guidance set out the level of engagement to expect from us. 

The focus of our engagement, and any bespoke advice we give, will be on natural heritage issues of national interest.  Our framework for determining issues of national interest is set out in our guidance on ‘Identifying Natural Heritage Issues of National Interest in Development Proposals’.  This guidance is particularly relevant to identifying impacts that may raise issues of national interest beyond protected areas of national or international importance. Our level of engagement and the scope and detail of our advice will be in proportion to the nature, scale and importance of the potential impacts. 

The absence of specific comments from us on a proposal should not be interpreted as meaning there are no other significant effects that need to be considered, either within the scope of an EIA or when determining applications.  Where we do not provide case-specific advice, our standing advice (including this pre-application guidance) should help inform the scope of any application/EIA.

Developers and consultants should allow sufficient time in a project plan to accommodate our advice. Our typical customer care timescale for responding to pre-application advice requests is within 20 working days but there can be delays in responding when other statutory consultations take priority.

We use a platform called InformedDECISION for all our pre-application enquiries and statutory consultations.  Guidance on how to use the platform is available on our InformedDECISION webpage.

Any information submitted to us during pre-application discussions may be subject to a request under the Environmental Information (Scotland) Regulations 2004.  For this reason, although we are happy to receive information about the proposal at the pre-application stage, we cannot do so on the basis that we hold that information in confidence.  Developers can take some steps to help us manage information by separating out, and clearly marking, environmentally and commercially sensitive information, and  providing us with an explanation of the harm that would occur if any particular information was released. 

It is worth noting that we only wish to be consulted on the discharge of planning conditions applied at our request to avoid an outright objection, or if we have otherwise agreed to be consulted. Therefore, we prefer not to be written into any planning conditions proposed in advance within EIA reports. 

Advice to help inform an EIA

Our website includes a range of guidance and information to help ensure that developers undertake a robust assessment. Our guidance is subject to periodic review, so please ensure you are accessing the latest version from our website. The complete list of our standing advice and guidance helps provide easy reference to latest versions of documents. 

This pre-application guidance highlights some key standing advice relevant to solar farm applications, and provides some advice not covered in our other published guidance. 

Landscape

General advice for all proposals

Where there is potential for significant landscape and visual effects, an assessment will be required.  This should encompass the potential effects of any associated infrastructure such as access tracks, security fencing, lighting and substations. 

Assessment should follow the Guidelines for Landscape and Visual Impact Assessment (GLVIA 3). This should include a Zone of Theoretical Visibility (ZTV) map to indicate where the arrays might be seen from, and a viewpoint analysis based on key viewpoints throughout the surrounding area.  The number of viewpoints will depend on the scale of the proposal and visibility within the surrounding area.  In some circumstances, where there is related potential for likely significant effects, the LVIA should include an assessment of the impact of glint and glare. In keeping with GLVIA, cumulative effects should be considered. 

To help achieve more consistent standards, we recommend that visualisation-related materials (photographs, wirelines and photomontages) are produced following the principles outlined in the Landscape Institute Technical Guidance Note 06/19 Visual representation of development proposals. 

The sensitivity of a landscape to solar development will often depend on its landscape character.  A Landscape Character Type dataset for all Scotland is available on our website at Landscape Character Assessment in Scotland.  Siting and design should take account of key aspects such as landscape scale, landform and land cover.  With appropriate siting and screening the visibility can often be minimised for ground-mounted panels. 

National Scenic Areas and National Parks

National Planning Framework 4 (NPF4) Policy 4(c) states that development proposals that will affect a National Scenic Area (NSA) or National Park should only be supported where:

• The objectives of the designation and the overall integrity of the areas will not be compromised; or
• Any significant adverse effects on the qualities for which the area has been designated are clearly outweighed by social, environmental or economic benefits of national importance.

Where significant effects on the special qualities are likely, developers should refer to our website information and advice on  NSAs and  National Parks, Including our guidance on assessing effects on Special Qualities of NSAs and National Parks. 

Wild Land Areas

NPF4 has significantly changed policy relating to Wild Land Areas (WLA).  There is now a greater distinction between policy requirements for developments within and outwith WLA, and certain types of development within WLA are now supported. Annex A of our guidance Identifying Natural Heritage Issues of National Interest  sets out how we will respond to proposals of different types within and outwith WLA.

NPF4 Policy 4(g) indicates that only certain categories of development proposals will be supported within WLA.  These include where the proposal will support meeting renewable energy targets (this encompasses proposals to generate, transmit and store renewable energy).  All such proposals must be accompanied by a wild land impact assessment which sets out how design, siting, or other mitigation measures have been, and will be, used to minimise significant impacts on the qualities of the WLA, as well as any management and monitoring arrangements where appropriate. 

Our advice and guidance on WLAs should be applied to proposals in WLAs whose nature, siting, scale or design are likely to result in a significant effect on the qualities of a WLA. 

NPF4 Policy 4(g) states that buffer zones around wild land will not be applied, and effects of development outwith WLAs will not be a significant consideration.  However, in seeking the best design solution for a proposed development, the wild land assessment guidance (which compliments the approach set out in Guidelines for Landscape and Visual Impact Assessment) is a useful process by which the significant effects are identified and can potentially be mitigated through appropriate design iterations.  Wild land assessments may also help to inform the decision maker about the full range of significant effects for proposals sited outwith WLAs. 

Local Landscape Areas

Our website provides helpful general information on Local Landscape Areas (LLAs), with site-specific information and advice on LLAs available from local planning authorities. 

Birds

The main potential impacts are likely to arise through habitat loss, displacement and disturbance (during construction and operation), all of which may affect breeding, foraging and roosting birds.  Published evidence suggests the overall risk of collision is low for solar PV, and we advise there is no need for a collision risk assessment. 

We advise that some form of distribution and abundance surveys will typically be required, and that these should be undertaken following the methodologies detailed within Section 3.7 of our wind farm bird survey guidance.  The surveys should be proportionate to the scale and location of the development.  

During the breeding season, the type of distribution and abundance survey will vary according to the habitats at and within the vicinity of the proposed development and the species likely to be present.  It is expected that the most common surveys required might be for moorland birds using the Brown & Shepherd (1993) method (amended by Calladine et al., 2009), raptors and short-eared owl using the Hardey et al. (2009) method and lowland waders using the Gilbert et al. (1998) method.  

Non-breeding season bird surveys may also need to be considered, for example, as noted at Section 3.7.2 of the survey guidance in relation to communal roosts for raptors, and at Section 3.7.8 in relation to wintering and migratory waterfowl. 

Up to one year of bird surveys will typically be appropriate for most solar PV farm developments, although developers and consultants must clearly demonstrate that the chosen duration is robust and appropriate to the specific proposal.  Additional survey work beyond one year may be required in some cases, for example:

• To potentially enable further detailed assessment of impacts of birds on, or connected to, protected areas, such as Special Protected Areas (SPAs); and
• In areas where bird sensitivity is expected or has been shown to be high, especially where activity varies significantly between years.

The ecological assessment should allow the identification of any significant cumulative impacts arising from the proposal in combination with other relevant developments.

Our standing advice note on planning consultations and birds should further help applicants submit proposals that minimise impacts. 

Applicants should consider the opportunities to incorporate biodiversity compensation and enhancement measures for birds.  Focus should be on the species that are most affected by the proposal, but Local Biodiversity Action Plans and specific species initiatives can also help identify species that are a priority for action. 

Bats

Our standing advice for batsshould be referred to inform survey, assessment, mitigation and any licensing requirements. Solar PV farm developments should be designed and constructed to avoid damage or disturbance to bat roost sites and to minimise any loss or fragmentation of foraging and commuting habitat.  The risk of collision for solar PV farm developments is low so bat activity surveys are not required.   

Other protected species

The presence (or potential presence) of other legally protected species also needs to be factored into the planning and design of solar development proposals.  Our website provides an A-Z guide on which species are legally protected. 

Any impacts on protected species must be fully considered prior to the determination of the application, and if there is evidence to suggest that a protected species is present on site or may be affected by the proposed development, steps must be taken to establish this and assess potential impacts. Our standing advice for protected specieshelps set out survey (and mitigation) requirements for a range of species. The assessment should include consideration of how construction works (e.g. piling), security fencing and lighting installations may affect local ecology. 

Applicants should consider opportunities to incorporate biodiversity enhancement measures for protected species.  Our Developing with Nature guidance does not include more specialist measures applicable to rarer species but does encompass a range of possible measures that will support more common species as well as some that enjoy special protection.  Local Biodiversity Action Plans and specific species initiatives can help identify species that are a priority for action and upon which work might focus. 

Deer

If wild deer use the development site, you should assess the implications of the development on deer and the indirect impacts on other interests (e.g. habitats, neighbours, roads, etc.).  You should present the assessment as part of your EIA report or application, even if you conclude that impacts are unlikely.  The assessment may indicate the need for management to avoid adverse impacts.  If so, we advise the need for a deer management statement, either as part of a Habitat Management Plan or as a stand-alone document.  For some sites, the modification of an existing Deer Management Plan covering a wider area may be more appropriate.  We do not expect developers to exert control over land that they have no rights over.  However, we encourage a collaborative approach with neighbouring landowners and managers to avoid adverse impacts on the interests of all parties.  A deer management statement may be included amongst the EIA report’s submitted mitigation measures, or produced to comply with a planning condition.  See our guidance on what to consider and include in deer assessments and management at development sites. 

Survey ‘shelf life’

Survey ‘shelf life’ relates to how long we consider that survey results remain valid before an updated survey is required.  Our standing advice notes for protected species and our bird survey guidance contain our advice on this.

Terrestrial habitat survey 

Solar farm proposals, including any associated buildings and access tracks, may result in habitat loss, fragmentation and modification. However, they also provide a good potential opportunity for habitat creation and improving nature networks. 

We advise that habitat surveys should include: 

• Phase 1 habitat survey
• National Vegetation Classification (NVC) survey of habitats listed on Annex 1 of the EC Habitats Directive and UK Biodiversity Action Plan (UKBAP) Priority Habitat, accompanied by supporting vegetation quadrat information
• Records of any rare and scarce plant species

We have adopted the European Nature Information System (EUNIS) as our standard habitat classification system for terrestrial habitat data and mapping.  We therefore recommend that all habitat surveys should also include EUNIS codes. We have published a manual and correspondence tables for EUNIS habitats in Scotland.The UK Habitat Classification (UKHab) survey can be used in place of a broad Phase 1 habitat survey but has not been fully validated in Scotland. There is a JNCC interactive spreadsheet of habitat correspondences (2008) which may be helpful to show how different habitat classifications relate to one other.

The habitat assessment should encompass all areas affected by the development including, for example, habitat indirectly affected by hydrological changes.  It should consider earthworks associated with construction compounds, access roads and cable trenching.  There should also be related assessment of habitat condition, e.g. as affected by grazing pressure, drainage, burning etc.  There may be cases where important habitat types are affected but they are currently in a degraded or unfavourable condition.  It is essential not to under-estimate the importance of habitats in sub-optimal condition where there is potential for restoration.

Example opportunities for site-specific mitigation, compensation and enhancement measures are outlined in the section below on delivering positive effects for biodiversity. 

Peatland

Peatland is an important habitat supporting biodiversity, and peat accumulated below ground is a key carbon store. 

There is currently a lack of evidence about how installation and operation of a solar farm might affect peatland.  However, we know that peatland habitat can be easily disturbed, and a reduction in sunlight and rainfall below panels is likely to affect vegetation composition and potentially the hydrological function of the peatland.  A reduction in sunlight reaching vegetation under solar panels could cause a significant decrease in the abundance and cover of peat building vegetation such as thick branched sphagnum species. This, combined with potential changes to the hydrological regime of the peatlands due to panels interfering with rainfall patterns, could cause further impacts on the potential of the peatland to sequester and store carbon.

Proposals should therefore seek to avoid peatlands where possible and minimise peatland loss and disturbance.  On a precautionary basis, we advise that the area under solar panels is considered as loss of peatland, together with any other direct and indirect peatland loss associated with access tracks and other ancillary structures. 

NatureScot’s consultation advice will focus on peatland habitat while Scottish Environment Protection Agency (SEPA) advice will focus on peat and carbon, including hydrological effects. These differing roles are outlined in the Joint working arrangement between SEPA and NatureScot on planning consultations. 

For proposals where peatland is affected, our detailed advice is contained in our guidance on Advising on peatland, carbon-rich soils and priority peatland habitats in development management.  To help assess the quality of peatland across the site, we request that the template provided in Annex 1 of this peatland guidance is completed and included with the application. 

NPF4 Policy 5d requires that ‘where development on peatland, carbon-rich soils or priority peatland is proposed, a detailed site-specific assessment will be required’.  The Carbon and Peatland map 2016 is a useful guide to screen where areas of peatland are likely to occur, but should not be regarded as definitive.  Whether in the Carbon and Peatland 2016 mapped area or not, proposals on peatland should be supported by a site-specific and detailed peat survey. in addition to the more general habitat survey information referred to above. This should be undertaken in line with Scottish Government peatland survey guidance. 

Compensation and enhancement measures should be set out in a sufficiently detailed outline Habitat Management Plan (HMP) submitted with the application.  (see Annex 2 of our peatland guidance).  Our detailed peatland guidance also provides our recommendations on the amount of restoration needed to compensate for any peatland loss and to deliver additional biodiversity enhancement (see further advice in final section below on delivery of positive effects for biodiversity).

Peatland ACTION has an interactive peatland restoration data mapping portal.  This provides a resource for checking any potential overlap between existing Peatland ACTION restoration projects and development sites.

Woodland

If tree felling/ woodland clearance will be required as part of the proposed development, we recommend that developers contact Scottish Forestry at as early a stage as possible to discuss theControl of Woodland Removal Policyand the implications it may have on the development. 

Freshwater

We recommend that, as a minimum, all areas directly (e.g. watercourse crossings) or indirectly (e.g. sediment run off) affected by the development and appropriate buffers up and downstream should have a habitat survey. This should inform the likelihood of the presence of salmonids, eels, freshwater pearl mussel and other protected/ Biodiversity Action Plan (BAP) species and so the need or otherwise for species-specific surveys. 

Where there is connectivity to protected areas, e.g. river or loch Special Area of Conservation (SAC), then a higher level of targeted survey effort and assessment may be needed (e.g. to inform an appropriate assessment for a SAC). 

Note that where there is suitable habitat for freshwater pearl mussel, and particularly where salmonids are present, we would expect survey following the method referenced in our standing guidance for freshwater pearl mussels. 

Access and recreation

Consideration should be given to the existing and potential use of the area for recreation by the general public, with reference to Scottish access rights under the Land Reform (Scotland) Act 2003 and rights of way. 

Planning authorities including National Park Authorities have a duty to uphold access rights within their areas.  These authorities have a lead role in advising on access management within the development site, including the effects of the development on existing access and opportunities for improved access provision.  We recommend that developers engage with planning authorities in the preparation of an access management plan, if required, on a case-by-case basis.  This plan should identify the current recreational activities in the area and any positive or negative impacts that may occur as a consequence of the development during both construction and operation.  

Design and layout of the site should ensure continued access, where possible, during construction and when operational.  Whilst access rights may be suspended while construction work is actively taking place, except for on core paths and rights of way, the suspension should be for the minimum area and time possible.  Interpretation and temporary diversions may be appropriate. 

Delivering positive effects for biodiversity

NPF4 sets out new requirements for development to deliver positive effects for biodiversity, primarily under Policy 3.

For national and major developments, or those subject to EIA, Policy 3b notes that proposals will only be supported where it can be demonstrated that they will conserve, restore and enhance biodiversity, including nature networks, so they are in a demonstrably better state than without intervention. The policy requires that such proposals demonstrate significant biodiversity enhancement, in addition to any proposed mitigation.  Only when actions result in biodiversity being left in a better state than before development are positive effects secured. 

The Scottish Government Draft Planning Guidance on Biodiversity (published November 2023) provides further advice on delivering biodiversity enhancement to clarify understanding of NPF4 Policy 3.  Although labelled as “Draft Guidance” it is intended that it should be used now to assist in implementation and delivery of Policy 3.

Our Developing with Nature guidance has been prepared, in discussion with Scottish Government, to support local development applications.  It sets out a number of common measures to enhance biodiversity that are widely applicable.  For national, major and EIA developments, more detailed assessment and more ambitious measures are likely to be required. To help with this and further support delivery of NPF4 Policy 3b, we are currently undertaking work, commissioned by the Scottish Government, to develop a biodiversity metric for Scotland’s planning system.  For information and updates, please see our enhancing biodiversity webpage and our biodiversity metric for Scotland’s planning system webpage. 

Selection of the development site will be important and ‘mitigation by design’ can also help avoid and/or minimise effects on the more sensitive parts of a chosen site.  Site-specific measures to enhance biodiversity (and landscapes) may include:

• ­Retaining, infilling and establishing native trees and hedges for the benefit of both screening and biodiversity.
• Minimising the use of security fencing and lighting where possible to reduce any adverse visual impacts or adverse effects on ecology and access/ recreation.
• Considering the availability of natural features/defences such as steep gradients, hedging and rivers to help minimise the use of security fencing.
• Minimising the height and intrusive design of security fencing where possible, and considering potential for screening of fencing using existing hedges or landscaping.
• Marking fencing with deflectors to reduce risk of bird strikes in higher sensitivity locations.
• Incorporating mammal gates/gaps into fencing.
• Establishing and maintaining wildlife buffer strips between and around arrays.
• Directing security lighting away from areas of valued habitat and using passive infra-red (PIR) technology (we note that security lighting is generally resisted on solar sites due to largely being in rural locations).
• Minimising disruption and ground disturbance on sensitive habitats such as peatlands through sympathetic installation and maximising the use of existing infrastructure (e.g. access and cabling adhering to the routes of existing tracks).  Installing using pile driven or screw foundations rather than trench foundations where possible, particularly on more sensitive habitats.  This will help reduce reliance on concrete, minimise ground disturbance and facilitate restoration.
• Where soil stripping or trenching is necessary, stripping, storing and replacing topsoil and subsoil separately in order to minimise soil damage and to provide optimal conditions for site restoration.
• Minimising the use of chemicals to clean panels.  Plain water is preferable, especially over peatlands.
• Minimising potential for disturbance through a sympathetic maintenance regime. For example, on peatlands cleaning could be done as infrequently as possible in order to minimise drainage and compaction impacts associated with trampling.
• Employing vegetated roofs (in keeping with local habitats), where appropriate, on associated buildings and cladding or screening these to help reduce visual impacts.
• Maintaining appropriate grazing management in relation to proposals for habitat restoration/creation.
• Installing heights of frames that allow effective sheep grazing where relevant.
• Incorporating wider biodiversity enhancements such as habitat, nesting and roosting boxes, and locally appropriate plant mixes for pollinator species.
• Considering invasive non-native specieswhere appropriate.
• Facilitating enhancements to the local path network, where appropriate. 

Several of the above measures, and others, are covered in more detail in Annex A of our Developing with Nature guidance.  The Annex describes 24 biodiversity measures that can be incorporated into development, grouped into three categories: planting for nature; providing homes for nature; and managing water with nature.  This is not an exhaustive list, and other innovative or bespoke measures may be required for some developments.  

Solar Energy UK’s Natural Capital Best Practice Guidance includes further useful information on mitigation and enhancement measures. 

Additional advice can be found in our guidance on What to consider and include in Habitat Management Plans.