The Aviary Estate Windmill Lane Southall UB2 4NG Data via plota.co.uk

The London Plan gives Metropolitan Open Land the same protection as green belt: inappropriate development needs very special circumstances.

Registered parks and gardens, battlefields, world heritage sites and protected wrecks are designated heritage assets: harm needs clear and convincing justification.

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.

The council or Historic England considers archaeology likely here. A desk-based assessment, and sometimes trial trenching, can be asked for with the application.

Schemes that add traffic, parking or combustion plant are assessed against the area's action plan and may need an air quality assessment.