built extension over the boundry by 100mm, need advise

[kingandy2nd]

I[t]was a genuine mistake .

Yes, but a mistake by who? Have you self built or has the work been done by a builder?

Who was responsible for setting out of the building and thus caused this mistake?

If it was another party (and not yourself) then I would be insisting that they rectify at their cost.

You're just leaving yourself open to future headaches with the neighbours or when you come to sell.

I guess it was you that set out then pee1

 

[pee1]

No. Builder built 6'' from neighbour's extension.

 

[tony1851]

A not uncommon mistake when there is already an extension next door.
When you can't see the original window next door, there is no easy way of dividing the gap between the two.

 

[Barlows]

Out of curiosity, if you had a fence like this and no visual indication on the brickwork of the attached house, where do you draw the line?

 

[jubbly1]

We had a similar boundary situation and executed a deed with the neighbour stating where the boundary was with pictures to illustrate. I think that you can do this for a few cms and as long as there isn't a disposal of land. Both mortgage companies gave consent and we registered it at the land registry.