party wall_extension near to neighbour private drain

Chazz82

Hi,
This is a question that is beyond the title. We are building a kitchen extension in a terraced property. We have planning permission accepted (we are in a heritage site). Our neighbours who did their kitchen extension two years ago are bing very difficult. When they built their extension two years ago they had to move their inspection chamber and do a little repair work to their drains (these are private drains not private sewers or public sewers - they only take their water/waste) and I think they moved the private drains slightly to accommodate their extension. We will also have to move our inspection chamber for our extension. When they built their extension the previous neighbour of our property agreed to an astrid party wall agreement. We wanted to extend the party wall by 1.6m as our extension goes out further, but they said no. So we respected that and plan to build the remaining 1.6m of wall on our side. The problem is that they put their inspection chamber and the drain of the rain water gutter almost on the boundary, if not over on our boundary. They had already put the garden fence on our boundary side, which they realise now they will have to move. The builder has explained to them that if the drain is where it should be he can just build up to it, but if it's not he may have to move it over a little bit. The neighbours weren't to happy about this. It's hard to see right now until we have a look what's under the ground. We now have to get a surveyor to deal with the party wall stuff, but I am not sure if he can really help with the drain issues. I guess my questions are, can we build right up to their drain,as long as it is on our boundary side? Are there not build regs in place that suggest inspection chambers are a distance from boundary lines? I am worried where all of this could end up going. All I want to do is build on my land that is rightfully mine and not have to compromise our building design. If it means we can't build from their side (no access) and they want no disruption we can do that. I just want to make this process as peaceful as possible. 
Also FYI - when they did their extension they definitely built way over the party wall area and encroached on some of our land. Due to the angle of our gardens we actually loose quite a lot of space for our extension. So you can see why I am keen to keep as much space as possible. I am feeling very unsettled by it all. 
Anyone with any advice I would be grateful, especially from a party wall surveyor and or builder with experience of building in and around private drains. 
Thank you.

Doozergirl

The party wall surveyor can deal with your drain issues.  Them and perhaps a structrual engineer.  

If your neighbour built astride the boundary then you should be attaching your extension to it.  That wall should form the inside wall of your extension.

have you actually engaged a party wall surveyor?   It doesn't sound like it.  It sounds like you politely asked your neighbours a few things and they refused.  That isn't how the PWA works.  

mcooke999

You need to engage a party wall surveyor.

Have you got any drawings which show the existing drain/manhole in relation to your new extension?