We automatically calculate most of the losses (and gains) in your site. There is one place we cannot do this, though, and that's for "linear habitats"—hedgerows, ditches, that sort of thing.

Why? Well, imagine a hedgerow running across your site, and crossing the area where you are building a new structure. Although it's likely that you'll take the hedgerow out within the floorspace of the new structure, we can't know if you'll retain it all the way up to the wall, or if you'll leave a short (or indeed, wide) gap.

This is why we ask you to quickly mark how much of each linear habitat you are going to lose. You just draw over the existing line, and we can then calculate what the impact of that loss is on your wider project.