DERLWYN Lôn Caernarfon, Llwyn Hudol, Pwllheli, Gwynedd, LL53 5YE Data via plota.co.uk

National policy refuses development that would cause loss or deterioration of ancient woodland or ancient trees unless there are wholly exceptional reasons.

Where development of farmland is needed, policy prefers poorer land over the best and most versatile (grades 1, 2 and 3a). Three sources: Natural England's post-1988 field surveys, which are definitive where they exist; the Defra predictive map for England (2025) and the Welsh Government predictive map, modelled from the soil map with 3a and 3b split; and the 1970s provisional map, which planners and other services still show, coarser and with grade 3 undivided. Where the provisional and predicted grades disagree, treat the predicted grade as the current estimate and expect an application to carry its own survey.