Planning applications in Caerphilly County Borough could take longer to process in future, if they are found to cover sites of local ecological importance.

The council’s environment committee has backed updated rules on defining Sites of Importance for Nature Conservation (SINCs), which will apply to every local authority department.

A committee report notes the changes could lead to “future financial implications” if developers bring forward plans for sites linked to SINCs.

This could include increased costs for site assessments, surveys, and any mitigation measures at the sites – as well as “extended planning and determination timescales”.

Cllr Haydn Pritchard asked how the council would manage these “potential bottlenecks”, and meet its housing targets without compromising its “vigorous new biodiversity commitments”.

Council biodiversity officer Margaret Iles said Caerphilly already uses previous guidance on SINCs in its Local Development Plan – the authority’s overarching blueprint for where building should take place.

She said sites already designated as SINCs are “very rarely brought forward” for proposed developments.

“In the future, any sites that do come in as a planning application, they will be asked for an assessment for these criteria to be taken against the site first, to make sure these sites do not qualify as SINC status,” Ms Iles explained, adding that even if sites do qualify, “it doesn’t rule them out straight away”.

She said that “in some circumstances, depending on the habitat and species present, mitigation measures can be discussed and incorporated at the early stages to make sure there’s no loss of biodiversity”.

But developers should check sites for possible SINC status as soon as possible, she warned, telling the committee doing so in “the early stages [is] always a cheaper option than waiting until the final hour”.

The new SINC criteria will be incorporated into the council’s next Local Development Plan, which is currently being put together after several delays.

Cllr Chris Morgan, the cabinet member for green spaces, said SINCs did not have the same legal status as Sites of Special Scientific Interest (SSSIs), but “are recognised through planning policy and play a vital role in maintaining ecological resilience, protecting biodiversity and contributing to nature recovery across the county borough”.