Have you looked at the government's explanatory booklet? If not see below:
What do your deeds say about ownership of the wall 4-6? This seems to be the principal root of the problem: if it's your's (either solely or shared with your upstairs flat) then I still feel it's nowt to do with the act and therefore no notice is required on no 4 and you should be under no obligation to pay for a surveyor who was not needed.
It is a sad fact of life that builders, curtain makers and the like check planning lists to tout for business and pester the applicant while PWSs pester the neighbours: "your property is potentially at risk and we will protect your interests at no cost to you" is a powerful lure. I always advocated to my clients that talking to neighbours early on was the best way to go. On several occassions, including my daughter's place, the neighbours were also considering a rear extension so they shared a party wall saving a fair bit of cost and giving more space.
I fear you have employed a less than competant guy who is weak and the neighbours one appears to be a bit of a rogue. I'm not sure how this sorry saga is going to end but I have a horrible feeling you will need the 3rd surveyor though if your neighbours guy has behaved unprofessionally you should go to RICS with a formal complaint.
What do your deeds say about ownership of the wall 4-6? This seems to be the principal root of the problem: if it's your's (either solely or shared with your upstairs flat) then I still feel it's nowt to do with the act and therefore no notice is required on no 4 and you should be under no obligation to pay for a surveyor who was not needed.
It is a sad fact of life that builders, curtain makers and the like check planning lists to tout for business and pester the applicant while PWSs pester the neighbours: "your property is potentially at risk and we will protect your interests at no cost to you" is a powerful lure. I always advocated to my clients that talking to neighbours early on was the best way to go. On several occassions, including my daughter's place, the neighbours were also considering a rear extension so they shared a party wall saving a fair bit of cost and giving more space.
I fear you have employed a less than competant guy who is weak and the neighbours one appears to be a bit of a rogue. I'm not sure how this sorry saga is going to end but I have a horrible feeling you will need the 3rd surveyor though if your neighbours guy has behaved unprofessionally you should go to RICS with a formal complaint.

