It is recommended that SINCs are surveyed and reviewed every 5-10 years. The availability of budget, staff resources, expertise and experience across London Boroughs varies and can therefore influence this timeline and the decision to do a partial or full review. Some boroughs chose to time SINC reviews with their Local Plan, so they are adopted imminently once reviewed. If SINCs have been reviewed and the Local Plan is awaiting adoption, the sites can be added to GiGL’s proposed SINC database once they reach Regulation 18, so they continue to inform the planning process (see below for further information).

Proposed SINCs (pSINCs) are candidate sites or proposed changes to the boundary or grade of a current SINC. They have been identified through SINC review, so meet the SINC criteria, and have entered public consultation (starting from Regulation 18) but are awaiting formal adoption through the Local Plan process.  Accordingly, this category typically applies only where a mid-term SINC review is completed.

GiGL collate pSINC data from boroughs so the information can still benefit planning and conservation decisions despite not being adopted. However, the dataset is used by some but not all boroughs, for example, depending on the time lapse between completion of a SINC review and the Local Plan adoption.  Accordingly, the absence of pSINCs cannot be taken necessarily to indicate the absence of any candidate sites meeting the SINC criteria.