Neighbours new extension, How to maintain my wall

Hi, I was wondering if anyone has any experience in this.
I live in a semi detached property and my new (semi) neighbour has submitted plans to build an 5metre extension to the rear of his house, our home already projects 4 metres further than the rear of his property due to an extension in the mid 70's.
His proposal rather than tie-ing into my existing wall is to build a new wall with a 50mm gap between our properties.
My issue is that we have been advised by our surveyor that our wall ties will need replacement in the next couple of years. Covid has unfortunately hit earnings so I cannot afford to have this done before he will have built his extension, meaning there will be no way for me to access my wall to carry out the repair.
Does anyone have any thoughts / advice please? Can the repair be done internally, does the gap need to be wider to allow access knowing the issue, etc.
Thanks all

I would say sadly you need to bite the bullet and get it done now. I had it done a couple of years back and while I cannot see any reason in theory it cannot be done from inside the mess noise and disruption would be horrendous!

Time to start talking Party Wall Agreements even if you loose a couple of inches of land. a 2inch gap will cause horendous damp issues cause there is an easy means of keeping rubbish out of such a small gap.

Swamp people in the making...

wgt52 said:

Time to start talking Party Wall Agreements even if you loose a couple of inches of land. a 2inch gap will cause horendous damp issues cause there is an easy means of keeping rubbish out of such a small gap.

Click to expand...

"Is?"

wgt52 said:

a 2inch gap will cause horendous damp issues cause

Click to expand...

No it wont and doesn't

The work can be done internally, but a lot depends on what masonry materials you have and what system of ties is proposed. It's certainly more disruptive though.

With the additional shelter the neighbour's new wall will provide it may well mean that the tie situation abates for a while or for good. And it may also be so that if the issue is the external leaf, as is common, you may not need to deal with the ties at all.

Your surveyor seems to have specifically narrowed down the time period for this type of repair, which is very unusual.