 National Planning Policy Framework 2024

Chapter 15: Conserving and enhancing the natural environment.

 London Plan 2021

Chapter 8: Green Infrastructure. Specifically, Policy G6 Biodiversity and access to nature.

 London Environment Strategy (LES) 2018

Appendix 5 provides guidance on the SINC selection, extracted from the previous GLA SINC advice note (2019).

Chapter 5 ‘Green Infrastructure’ proposal 5.2 1a addresses SINCs and London Plan policies relating to SINCs recognising biodiversity and access priorities.

Objective 5.1 and 5.2 provide two quantified objectives relating to the role of the SINC network in protecting priority habitats.

 Environment Act 2021

Part 1 Environmental governance, Chapter 1 Improving the natural environment.
Part 6 Nature and biodiversity (BNG & LNRS).

 London’s Local Nature Recovery Strategy (LNRS)

Published in 2026, it is recommended that boroughs use the LNRS to align Local Nature Recovery Plans in accordance with individual Local Plan cycles.

 Natural Environment & Rural Communities (NERC) Act 2006

Part 3 Wildlife etc., Section 41 Biodiversity lists and action (England) & Section 40 Duty to conserve and enhance.

 Wildlife & Countryside Act 1981

Chapter 8: Informs the assessment of core criteria for SINC designation.

 The Conservation of Habitats and Species Regulations 2017

Outlines the Regulations affording internationally recognised protection to rare habitats and species at the European level. Where such designated sites overlie SINCs, greater protection is afforded in the development planning system.

 National Parks and Access to the Countryside Act 1949

Informs statutory instruments for Sites of Special Scientific Interest (SSSIs) designations, and of National and Local Nature Reserves (NNRs and LNRs, respectively), which, when overlapping with SINCs, provide greater protection in the planning process.

 London’s Green Infrastructure Framework (LGIF)

A London-wide strategic evidence tool designed to support the planning, delivery and long-term management of green infrastructure. The LGIF consolidates key data into resources to help guide decisions on where and how green infrastructure can deliver the greatest social and environmental value.

Published in March 2026, the LGIF replaces the 2018 GI Focus Map and the 2012 All-London Green Grid.

Scoping a SINC review can follow a ‘nested approach’ ranging from borough-wide to partial reviews. The nested approach recognises cross-boundary SINCs and may be applied to SINC reviews undertaken in combination, for example, with a Public Open Space strategy.

This approach covers a range of reviews:

• Comprehensive: strategic review of the entire borough’s ecological network, including habitat functions, weaknesses, and opportunities, with consideration of cross-boundary connections to inform local plan updates as well as wider strategy development or planning for nature recovery delivery.
• Full SINC network: Includes all SINCs, ensuring private or partially accessible sites are considered early for access and survey planning.
• Partial: Focuses on select SINCs, guided by a rapid borough-wide assessment to identify sites that have changed significantly since the last review and/or those which are not currently SINCs but could meet the thresholds to be selected.

The type of review will depend on several factors, such as: 

• New development proposals requiring assessment of potential impacts on SINCs.
• Emerging evidence indicating changes in habitats or species.
• Funding constraints, where a full review is not feasible.
• Targeted site assessments, when there is already strong knowledge and evidence indicating some sites remain unchanged.

LPAs conducting a SINC review should ideally:

• Initiate the process at the very start of the Local Plan review process and consider the frequency and speed of public consultations.
  Note that a SINC review may commence outside of the Local Plan review cycle due to various needs. This can be beneficial in ensuring up-to-date information is available for SINCs, both designated and new, so they can be fully considered in strategic land planning. 
• Consider survey seasonality, principally for habitats. Consult your chosen ecologist for advice on timings and schedules. See LUC’s Ecology Survey Calendar for guidance.
• Consider the speed and frequency of public consultations and the London Wildlife Sites Board (LWSB) consideration process. Consult the LWSB for advice on their timings and schedules.

At an early stage, LAs can choose to add value and additional steps to a SINC review by combining methods with:

• Assessments of parks and public open space, play areas, or sports facilities to provide a more comprehensive understanding of local green infrastructure
• Biodiversity Net Gain (BNG) assessments.
• Complimentary surveys using AI or innovative technologies, such as remote sensing or drone surveys.

All of the above can be incorporated into the specification for contractors at the next stage.

A Local Biodiversity Panel is a time limited task and finish group that should be established to help identify which sites should be included in a review and to evaluate the recommendations in a local borough context. In the case of a partial review, the local expertise of the Panel will support prioritisation of sites to be surveyed, for example by highlighting non-SINC sites that should be included because of species or habitats they support.

The SINC Advice Note requires boroughs to establish a local panel, and it is the responsibility of the LA to convene one. Existing forums and partnerships should be used where established, such as Local Biodiversity Partnerships, to avoid duplication. Suitable participants for a Panel would include:

• Acknowledged local natural history experts (e.g. council ecologists or London Natural History Society members).
• Local wildlife group leads (e.g. local bat group, bird groups)
• eNGO leads actively working in the Boroughs
• London Geodiversity Partnership members

The chair of the group could be the Borough Biodiversity lead, or a member of the group voted in, determined by the panel’s terms of reference.

 Finding a Consultant | CIEEM

When the scope of the review is decided, LPAs can put out an Invitation to Tender (ITT) Specification to invite surveyors to submit a bid. The specification should typically include:

• Background: A description of the review process, outline of available existing information and, where present, the Local Biodiversity Panel members already engaged.
• Spatial scope: Existing SINCs and new candidate sites to be included or whether the identification of this is to form part of the work.
• Specifications: Detailed specifications of the requirements, including survey types and analysis required. The SINC advice note sets out the recommended process for selecting and confirming SINCs, including the policy, criteria and procedures for SINC assessment.
• Data requirements: Details on making effective use of available data, and the requirements for data collection and sharing. See the survey data standards guidance and accessing data sections for templates and further information.
• Delivery timelines: The required delivery dates to enable the local plan review to be developed taking into account up to date SINC information. The seasonality of field surveys must be considered.
• Evaluation criteria: The criteria used to assess tenders.
• Tender submission requirements
• Pricing format
• Terms and conditions

GiGL encourages local authorities to include terms in ITT specifications requiring surveyors to access the evidence base and share collected, standardised data with GiGL, enhancing data availability for informed decision-making.

Example wording: The appointed contractor will be expected to make full and effective use of Greenspace Information for Greater London CIC (GiGL), London’s environmental records centre. Newly acquired data on the natural environment (e.g. habitats, species, green infrastructure features) will be shared with GiGL, following GiGL’s data standards.

Applying GiGL’s survey data standards is vital to ensure results are easier to handle and integrate into London-wide datasets without losing information. This helps protect the value of survey investment and supports both current and future projects. View and download the suite of guidance below and get in touch with GiGL in advance of undertaking survey work to discuss plans.

 SINC Survey Data Standards

 SINC Citation Template

 SINC Areas of Deficiency Survey Data Standards

Guidance includes how to gather access point data, which is essential for the accuracy of AoD modelling.

 All Survey Data Standards Guidance

Other guidance includes general standards for all surveys, and specific standards for habitats, species and open spaces.

GiGL is the official custodian of information on London’s SINCs – including their citations and boundary information. GiGL works with all LPAs to maintain this information, whether they are partners or not, although some LPAs may choose to use their own datasets. Additionally, GiGL stewards a wealth of other datasets covering information on London’s natural environment, many of which can help in the SINC review process.

How to access data?

 Accessing GiGL Data | SINC Resource Hub

What data do GiGL hold?

 GiGL Data Holdings

 GiGL Data Guide

Recommended GiGL datasets for SINC reviews:

 Non-statutory SINCs

 Statutory designated sites – e.g. SSSIs and RAMSAR sites.

 Geodiversity sites

 Designated species

 Areas of Deficiency in Access to Nature

 Habitat Suitability Modelling

 Habitats

Other datasets

Note that the below are open government licence datasets and can therefore be shared via GiGL to save extra steps and time.

 Priority Habitat Inventory | Natural England

 Ancient Woodland Inventory | Natural England

 Flood Risk | Environment Agency

 Climate Risk Mapping | GLA

 London Tree Map | GLA

The SINC Advice Note sets out the recommended process for selecting and confirming SINCs, including the policy, criteria and procedures for SINC assessment:

 SINC Advice Note

Resources for identifying important species & habitats:

 Species designations

A list of legal designations affording species protections, as well as other notable (non-legal) designations relevant to review criteria and attributed in GiGL’s species dataset.

 Species Lists – follow this link to access the below resources:

• Greater London and Middlesex Axiophyte List: A list of plant species which are indicators of habitats of interest for nature conservation.
• London’s LNRS Priority Species Longlist: Created as part of the steps to developing the capital’s Local Nature Recovery Strategy (LNRS). The spreadsheet includes information on the primary habitat and practical measures deemed important for the recovery of each species deemed a priority.
• London Invasive Species: Invasive non-native species that are cause for concern and a potential threat to the value of London’s natural environment.
• London Priority Species: London’s priority species are those species we share our city with that are national priorities for conservation and those that are believed to be declining in London or beyond.

 London’s Biodiversity Action Plan

The archived London Priority Species and Habitat Action Plans created by the London Biodiversity Partnership (now dissolved) can also be a useful resource, though some of the information may be outdated.

Resources for considering the historic environment:

 Historic Environment Considerations for London’s LNRS

To complement London’s Local Nature Recovery Strategy (LNRS), Historic England has published guidance on identifying opportunities within the historic environment where co-benefits for both nature recovery and heritage conservation can be achieved. They provide resources to help assess sites for their historic significance and heritage assets, alongside advice, guidance, and relevant legislation to support informed decision-making.

Maximising survey investment:

 GiGL Survey Data Standards Guidance

Applying GiGL’s survey data standards is vital to ensure survey results are easier to handle and integrate into London-wide datasets without losing information. This helps protect the value of survey investment and supports both current and future projects. View and download the suite of guidance below and get in touch with GiGL in advance of undertaking survey work to discuss plans.

Recommendations for changes can be prepared in a document with mapping and visuals presented where needed. For each site considered in the review, the following recommendations can be put forward:

• Upgrade: sites recommended for an upgrade in designation.
• Retain: no change. Sites that have maintained their value, to the same grade, and at which no significant intervention for restoration, enhancement or creation are identified.
• Boundary change: sites recommended for a boundary update to include additional valuable habitats that contribute to the value of the SINC or, conversely, to remove habitats that have irreversibly declined and no longer warrant inclusion.
• New sites: sites that weren’t designated prior to review but meet criteria to become a SINC at the specified grade.
• Opportunity: sites with potential, through management and/or habitat establishment, to significantly increase in ecological value.  Potential changes in SINC grade will be set out.  This category will be informed by Strategic Creation Opportunities identified in the LNRS as well as opportunities recorded on site.
• At risk: sites facing potential downgrade due to ecological decline. These sites should retain their existing designation. However, action is required to ensure that the designation is retained and, where appropriate, to additionally enhance the value. Action here is a priority.
• Downgrade: sites that have changed significantly and irreversibly, and no longer represent the original grade.
• De-designation: sites that have changed significantly and irreversibly and no longer support SINC criteria.
• Other sites considered: the review can note sites that were considered and/or surveyed but judged not to meet criteria at the time of assessment.

Changes to SINC citations should also be included in recommendations.

Once recommendations have entered public consultation as part of local planning Regulation 18, they can be entered into GiGL’s proposed SINC (pSINC) dataset. These proposed sites and changes have not yet been officially adopted within a Local Plan. As there can be a long gap between SINC reviews and official adoption, GiGL have established this pSINC dataset to allow these proposals to be shared with GiGL partners and clients to benefit their conservation.

GiGL works closely with LPAs (whether partners or not) to collate, process and standardise pSINC data, including boundaries and citations. Please get in touch with GiGL’s Partnership and Communications Officer, Becky (becky.garden@gigl.org.uk) to add to this dataset or find out more.

 GiGL pSINC Timeline

Proposed changes are also reviewed by the London Wildlife Sites Board (LWSB). The board provides expert and independent advice on the review process and should be consulted on SINC reviews and proposed changes. They also ensure consistency and compliance with various policy frameworks.

 London Wildlife Sites Board

Before a Local Plan can be adopted, a government-appointed inspector must assess whether its proposed policies and changes are legally compliant, sound, and in line with the LA’s duty to co-operate with other public bodies. This process is known as ‘the examination’.

During this stage, the public can submit feedback to help the inspector determine whether the proposals should proceed as they are or require modifications to meet legal and policy requirements.

GiGL works closely with LPAs (whether partners or not) to collate, process and standardise SINC data, including boundaries and citations. Applying survey data standards is essential to ensure that GiGL can efficiently manage and integrate results into London-wide datasets without loss of information, thereby protecting the value of survey investment.

Areas of Deficiency (AoD) in Access to Nature: Areas where residents must walk more than 1 km to reach an accessible Metropolitan or Borough SINC.

Once SINC data have been updated, GiGL will calculate and update any consequential changes to access points and Areas of Deficiency (AoD) in Access to Nature. These data are then made available for decision-making and research through GiGL’s products and services, including data search reports for planning applications.

 Areas of Deficiency in Access to Nature

 SINC Areas of Deficiency Survey Data Standards

Please get in touch with GiGL’s Partnership and Communications Officer, Becky (becky.garden@gigl.org.uk) to inform us of upcoming reviews, data updates or enquire about AoD modelling.

Local Sites in positive conservation management

Defra annually requests a report from Local Authorities on Local Sites in positive conservation management. This is not legally mandatory but is strongly encouraged as part of local and national biodiversity monitoring. Find out more here:

 Local Sites in positive conservation management in England

Species monitoring:

Recording with GiGL improves species data for local sites and offers a great way to engage communities. Local authorities can embed monitoring in events, guided walks, youth nature clubs, or ranger-led surveys, using apps, spreadsheets or webforms to capture sightings on the spot. Teams can also run seasonal surveys or BioBlitz sessions to both collect data and train volunteers. For practical examples of how councils integrate public involvement with routine species recording, see Lambeth Council’s Just for the Record! article on the GiGL website. Discover recording methods below and get in touch with a member of our Community Team to discuss how GiGL can support further.

 Submit 1-20 Wildlife Records

 Regularly Record – using GiGL’s recording spreadsheet

 Recording Apps

Data feedback: 

If surveys are being conducted or habitat restoration is taking place on designated SINCs, it is important to share this information with GiGL. This ensures the data are incorporated into London-wide datasets, enhancing the vital data flow for London and ensuring the information can be shared to nearby initiatives and considered in planning. Follow GiGL’s data standard guidance to ensure generated data can be easily integrated:

 GiGL Survey Data Standards Guidance