Boundary help

[Optimistic Nick]

If the extension has been there for over 4 years it’s exempt from planning enforcement action by virtue of section 171B of the Town and County Planning Act 1990. Your neighbour can apply (and automatically be granted providing they can evidence the extension being there for at least 4 years) a lawful development certificate to regularise it.

Is that the same as making it her land though? Like squatter's rights? I can imagine that there is something that grants the neighbour an easement for the overhanging guttering after a period of time which might be the only point of contention, but Does the provision you cite mean that the land below is legally hers now too?

OP- are there any downpipes, drains etc on that wall?

[Van Halen]

I’m just speaking from a town planning (law) perspective. Land ownership is a completely separate matter.

The Council cannot make them knock it down or make alterations to it if it’s been there (without planning permission) more than 4 years.

Any land ownership matters will be between the OP and his neighbour and ultimately for the courts to decide and cost £££. The council will not get involved.

[Taunton Blue Genie]

Is that the same as making it her land though? Like squatter's rights? I can imagine that there is something that grants the neighbour an easement for the overhanging guttering after a period of time which might be the only point of contention, but Does the provision you cite mean that the land below is legally hers now too?

OP- are there any downpipes, drains etc on that wall?

I think that the law regarding squatters' rights has changed as I looked into claiming a two-metre strip at the bottom of my garden and which belongs to the college behind me. The colleague has no access to the strip as it has built a ten-foot high fence two metres inside its own boundary. However, not have I been tending to that strip for ten years (as it was originally overgrown with a mass of impenetrable brambles) I dug it over at the beginning of lockdown and it has now become a vegetable allotment. However, the research I did seemed to indicate that I can't simply claim it, as would have been possible twenty years ago.