Two planning questions ...

[TwoAndTwoEqualsChaos]

Is there a legal definition of a dormer? My neighbour has built something she calls this, thus saying she doesn't need planning permission, but no dormer I have ever seen has one brick wall, one wooden one and cover the whole of the roof at the narrower end of a typical "L" shaped terrace house.

Secondly, we returned from our holiday to discover most of her fence has been removed, so we have virtually no privacy at the back of our house and, indeed, caught her teenaged daughter gawping into our house from their back doorstep. It isn't the boundary fence, as we have a shared passageway running between us, but can she be made to replace it?

Sorry, that was meant to be a strike hour, not bold.

*sigh strike out!

I'm not an expert, but the rules for loft conversions without planning permission are at the government planning portal. Possibly the volume is too much, but I don't think the materials are relevent for whether planning is required (though building codes may be being violated).

Most garden fences aren't a requirement. I think you need to check your and her title and/or deeds (you can get them from the Land Registery to see if there is any mention of a responsibility to maintain a fence (not just a "boundary" - that doesn't have to be a fence). We once had a requirement to maintain a 6 foot brick wall at the back of our property, but only to "mark the boundary" on the side.