Buying a house - sewage pipe runs under the land and manhole

skotak29

We are in the process of buying a house. The water and drainage search report says that sewage pipe runs under the land. It doesn't clearly say what is built over it; however our solicitor has asked for buildover agreement or indemnity insurance from the sellers.
Is there anything else we should enquire before we make the purchase?

Also we have just received the homebuyer report which says the manhole is to the rear of the garage. Not sure how we missed that during our viewings. Anyways, we were planning to extend the house and build either a utility or extended kitchen in that part of the garden. Have been reading online and understood that it's quite difficult to move the manhole and building over it is also not a good option.

Not sure what do to. We don't know if there is another manhole at the property and how close/far another (at someone else's property) manhole is. Would that matter in any ways? Should we enquire about that?

Has anyone faced this situation before? Would be great if someone could tell me the cost of moving the manhole.

Any other advice would be hugely appreciated.

Could this be a big problem in the future and should we consider pulling out (of the purchase) as an option?

Thanks in advance.

Owain_Moneysaver

Manholes are usually where two or three pipes join at an angle, and they can't be moved. You would have to reroute the entire drain route.

What you don't seem to know is whether this 'sewer' is simple a drain from your or your neighbour's house, or whether it's a main trunk sewer possibly under quite high pressure.

Building over the former is usually no problem and the manhole is replaced with a double-sealed one with a screw-down cover which is fairly inconspicuous in a tiled floor.

Building over a pressurised main trunk sewer is a different matter entirely. It's like a water main but instead of cold clean water spurting as high as the house ... well you get the picture.

littlerock

Some older houses, mine included it is not documented and no one knows where the sewers run once they leave my garden. Our main sewer is shared with next door and our individual pipes meet a few yards from the house under our boundary fence - i have a manhole one side and he has one the other. We built a conservatory over our sewage pipe in the side return. The council asked us to put a mole down the pipe to see where it went. After tracking it 80 yards under the gardens beyond ours, with no indication of where it was going, they gave up and signed it all off.