SINC Resources for Developers
This section of the Hub outlines expectations, requirements, and best practices for those working on development projects near Sites of Importance for Nature Conservation (SINCs).
Local Plans are key to the identification and protection of SINCs. Local Planning Authorities (LPAs) are responsible for undertaking SINC reviews, which align with the Local Plan process.
These sites protect London’s most valuable wildlife and habitats, in line with national policies such as the National Planning Policy Framework (NPPF), as well as regional strategies such as the London Plan. The protection is non-statutory, although SINCs are still afforded protection from development or incompatible land uses within the planning system.
1. Why are SINCs Important?
SINCs helps to protect London’s rare and distinctive habitats and species. The SINC network offers people opportunities to connect with nature, which is linked to better mental and physical health, and childhood development. SINCs also provide essential ecosystem services, such as flood management, urban cooling, and air quality improvement, supporting a more sustainable and resilient city. The understanding, protection and improvement of the SINC network not only benefits biodiversity but also enhances quality of life, making London a better place to live, work, and invest in.
SINC protection, and elements of their protection, such as the protection of important species and habitats, is outlined in policy and legislation.
SINC protection in legislation, policy & strategy
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.
2. SINCs in the Planning Process
Preliminary Ecological Appraisals (PEA) and Ecological Impact Assessments (EcIA) conducted as part of the development planning process should consider SINCs within the local area that may be affected by proposed developments. Assessments should align with guidance from the Chartered Institute of Ecology and Environmental Management (CIEEM), ensuring that the scope reflects the nature and scale of the development, as well as the sensitivity of the SINC as a potential ecological receptor. Rather than applying strict buffer zones, the approach should be tailored to the specific context, ensuring appropriate consideration and mitigation of potential impacts.
3. Data in Ecological Surveys
Professional ecologists conducting desk studies for ecology reports or Biodiversity net gain (BNG) projects and plans should consult an up-to-date data search report from GiGL. Any data collected from surveys should then be shared with GiGL following their data standards. This ensures that survey efforts are fully utilised and that the data contribute to future initiatives and planning.
GiGL data search reports
Ecology consultants who consult a data search report have accessed a robust evidence base, have taken into account the local context of a site and have followed best professional practice as set out by the CIEEM. Find out more and request a report here:
Data Search for Consultants
Data searches include information and maps on the below datasets, within a radius of your site:
- Statutory Sites, e.g. SSSIs and RAMSAR sites.
- Non-Statutory, .e.g. Local Nature Reserves and SINCs
- Geodiversity Sites
- Designated species
- Habitats
- Open spaces
- Areas of Deficiency in Access to Nature
Head to the SINC Resource Hub Glossary for a summary of each dataset and see GiGL’s Data Guide for further detail.
GiGL Data Search Report factsheet
Find out more about the importance of data informing development planning here:
Natural Environment Data in Planning
Visit the SINC Resource Hub ‘Accessing GiGL Data’ page for further information on methods of data access:
Accessing GiGL Data | SINC Resource Hub
Other datasets
Note that the below are open government licence datasets:
Priority Habitat Inventory | Natural England
Ancient Woodland Inventory | Natural England
London Tree Map | GLA
Survey data standards guidance
Applying GiGL’s survey data standards is vital to improve the ease of handling results and enable their incorporation into London wide datasets without loss of information. This maximises survey investment by ensuring the data are preserved to inform current and future projects.
We would always encourage consultants to contact GiGL in advance of undertaking survey work to discuss specific plans. View and download the suite of guidance below:
GiGL Survey Data Standards Guidance
Developers can help to encourage data sharing by adding terms to consultant contracts.
Example wording: Newly acquired data on the natural environment (e.g. habitats, species, green infrastructure features) will be shared with Greenspace Information for Greater London CIC (GiGL), London’s environmental records centre, following GiGL’s data standards.
Find out more here:
Data Sharing from Development
Important habitats & species
Species and habitat richness and rarity are key factors for SINC designation, protection and management. Certain species and habitats are protected at both local and national levels, with some protections being legal and others informal or non-statutory, but still significant.
Species designations
A list of legal designations affording species protections, as well as other notable (non-legal) designations that are 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 Focus Species Longlist: created as part of the steps to developing the capital’s Local Nature Recovery Strategy. The spreadsheet includes information on the primary habitat and practical measures deemed important for the recovery of each focus species.
- 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.
4. Planning Requirements
Developers must comply with a range of environmental regulations aimed at enhancing biodiversity and green infrastructure in urban areas. A key policy in the London Plan requires all major developments to incorporate urban greening as a fundamental element of site and building design through the Urban Greening Factor (UGF). Nationally, the Environment Act 2021 sets out Biodiversity Net Gain (BNG) objectives, ensuring that projects deliver measurable improvements to biodiversity. These policies and regulations are designed to integrate nature into the built environment, supporting ecological resilience and sustainable development.
Urban Greening Factor
Additional Support & Resources
Further links & articles:
Parks, green spaces and biodiversity | London City Hall
Spaces Wild | London Wildlife Trust
Areas of deficiency explained | GiGLer Newsletter
The importance of high quality natural spaces for well-being by Dr Sarah Knight | GiGLer Newsletter
Accessing Wildspace | GiGLer Newsletter
Updating GiGL’s Areas of Deficiency | GiGLer Newsletter
Glossary
Explore key terms, acronyms, other land designations, and policies commonly referenced on the Hub, with clear explanations for quick understanding.
General resources for SINC management
Visit this page for an overview of organisations that manage SINCs and support their conservation. Discover key resources to aid SINC management.