A distinction is made between UAA outdoors and/or under low cover and UAA under glass or high accessible cover.

• UAA under glass or high accessible cover:

Includes areas of crops which, for all or most of their growth cycle, are covered by greenhouses or high cover (fixed or mobile), whose structures are usually made of wood or metal, and the cover is made of plastic sheeting or glass.

In the case of a mobile greenhouse (glass, rigid plastic or flexible plastic) that has been used as such, the area to be recorded is obtained by adding the different areas covered by the greenhouse.

However, if the greenhouse, fixed or mobile, has not been moved and the same area has been used successively, it should only be counted once.

For multi-storey greenhouses, only the base area should be recorded.

Specifically, the following crop groups are included:

- Vegetables, including melons and strawberries, grown under glass or high accessible cover

- Flowers and ornamental plants grown under glass or high accessible cover (excluding nurseries)

- Other arable land crops under glass or high accessible cover

- Permanent crops grown under glass or high accessible cover

- Other UAA under glass or high accessible cover

• UAA outdoors and/or under low cover:

The UAA outdoors and/or under low cover is the total area of arable land (arable crops and fallow land), permanent or woody crops, permanent grassland and kitchen gardens used by the agricultural holding.

Systems regarded as low cover include windbreak fencing, padding, seedbeds and outdoor sanding.