Neighbour externally insulating rear of terraced house

[scarletslass]

Our (nice) neighbours have let us know that they will be re-rendering the rear of their house this year, and said they may look to add external insulation at the same time.

They will need access to our back garden for scaffolding etc, which is fine, but if the insulation is added we will lose a few inches along the side return in our garden. This isn't really a problem, but my question is, they have mentioned us letting them know our "terms" for this - what would anyone suggest these should be?? Thanks!

Don't allow it as it is your 'land'. Unless you want to sell them the extra inches they cannot do it as it is over your boundary. You needs party wall surveyor that they need to pay for. What if you want to extend too- you can't allow this.

I agree. If they want insulation along that side return, it should be internal. It'll cost them a few inches inside, but it's no big deal.