GiGL is the official custodian of information on London’s more than 1,600 sites of importance for nature conservation (SINCs) – their citations and boundary information. This core dataset is one on which many of our products and services rely. Its accuracy is vital and we are constantly working with our partners to help them update and maintain this important collection of data.

Sites of Importance for Nature Conservation (SINCs)
– London importance

London’s equivalent of Local wildlife sites, these sites are recognised for the important habitats they support. SINCs are designated by a panel of local ecological professionals. This is a non-statutory designation, although SINCs are still afforded a high level of protection within the planning system. Development that negatively impacts on a SINC will only be permitted in exceptional circumstances and where mitigation can be proven from the beginning.

In London, SINCs are designated as one of a hierarchy of types.

Sites of Metropolitan Importance are selected on a London-wide basis.

Sites of Borough Importance (grade 1 and 2) are selected from candidates within each borough, so ensuring that borough has some sites identified.

Sites of Local Importance are the lowest tier of sites, selected to redress any remaining local deficiencies.

Selection of and changes to sites is the responsibility of the local planning authorities. The London Wildlife Sites Board provides guidance on selecting and confirming SINCs designed to ensure consistency and a process which is compliant with various policy frameworks.

Proposed SINCs (pSINCs)

In April 2021 GiGL launched the new proposed SINC (pSINC) dataset which holds information on sites that have entered public consultation (Local planning regulation 18) but have not yet been officially adopted within a Local Plan. As there can be a long gap between SINC reviews and official adoption, the pSINC dataset allows these sites to be shared with GiGL’s partners and clients to benefit their conservation.

For more information on the planning process please see our SINC timeline.