AntonyJ

Thanks for your replies. I contacted Anglian Water. They said that even without the basement they would require a diversion and not allow building over as we're demolishing and rebuilding rather than extending. They don't allow build overs on new houses.... The main reason I was looking at keeping the pipe where it is was too avoid having to reduce the footprint of the house to make room for the drain to be diverted around the boundary. So, can anyone recommend a good drainage engineer that covers Essex? Thanks

It must be common having to route services through the basement when building office blocks etc in cities, but I assume less so in domestic situations. We have a shared sewer running through our plot (4 properties are upstream). The current house we're demolishing has an extension built over this. I'm exploring adding a basement to our rebuild (we have planning permission for the above-ground rebuild). Re-routing the pipe around the build would be too big a detour to work with the falls I think. Had anyone come across this situation and how was it dealt with? Is it a complete no, or are there solutions, e.g. build a culvert/tunnel around it or seal inside a duct so it stays "outside" the building?