Built Up Area boundary

The Built-Up Area (BUA) boundary marks the distinction between built-up areas of the towns and villages and the countryside in order to apply the relevant land use policies effectively. The Mid Sussex District Plan (and accompanying Policies Map) defines the built-up area, and all areas outside the built-up area are defined as countryside. Most of the towns and villages in the District have a built-up area boundary, and these are shown on the Policies Map. Some of the smaller villages and settlements have no built-up area. For policy purposes, these are treated as being within the countryside.

Areas of low density, sporadic development on the edge of settlements and which are separated from the settlement by road or other physical feature are normally omitted from the BUA boundary
source: https://www.midsussex.gov.uk/media/5223/tp2-built-up-boundary-and-policies-map-topic-paper.pdf

On page 25 of the Bolney Neighbourhood Plan, it states:
The development of Bolney shall be focused within the Built-up Area Boundary as identified on the Proposals Map and on Map 2. Development proposals will ordinarily be supported within the Built-up Area Boundary subject to compliance with other policies in the Neighbourhood Plan.
Note that the area sketched in green below was added after the Neighbourhood Plan was made, to accommodate the 4 new houses built subsequently.

We would be very concerned if any re-drawn BUA boundary was to make adjacent parcels of land vulnerable to unwanted and unsuitable development.
This could occur if the land west of London Road was granted planning permission, i.e. commonly called "Seward's field".
This would create a BUA boundary with a 'hole' in the middle where the stream runs through and the land is boggy. All of this land would then be vulnerable to development, making flooding of the lower part of the village worse.