Extension and manholes/drains

[Nickijsmith]

DH and I are currently considering an extension on our house. We haven't had any professionals around yet to have a look if it is feasible as I am still tryng to convince hubby to think more seriously about it.
The problem is that in the area that we want to extend at the back of the house are 3 manhole covers. Does anyone have any experience of moving drains and know how expensive it is, who we contact about moving them etc.

Place marking

I don't know about how much, but my MIL couldn't do it at all. There's one either side of her tiny conservatory and they point blank said no.

Think she spoke to the council

Place marking? whats that?

Daffodil90 - oh bugger, I bet they will definitely say no then!

Place marking - they want to see the answers too.

It could just have been our daft council but it's a place to start I guess!

We have just built a side extension where there is a main drain manhole thingy that has a drain that divides then goes to our next door neighbour and to our house

So we have had 2 options building over it leaving the man hole cover under the floor which is obviously well dodgy and could be very messy

The other option which is the one we took is to pay the water company some money iirc £135 so they could check the plans

We then have a sort of alcove thingy around the man hole with a door so we can access it from the house and also the neighbour can access it from the outside from over her wall

so we have a sort of porch area between the two rooms on side extension

it was more expensive as the builders and roofers etc had a more complicated job but it actually looks quite good and it means that we have lots of light coming from the south side into the window of the door

so it was deffo worth choosing option 2

a good architect is essential though as they know the way round the systems

we also had a video made of all the pipes going to both houses to check the pipes before they started to build

good luck everyone

there was no issue with planning dept at all at council

You need a build over agreement from the water company
If you don't get permission it could cause problems when you sell.

I did this recently on my extension, where I had a manhole in what would be the footprint of the new kitchen. I was with Thames Water - it cost £299 to apply for the Buildover Agreement. You will probably need to submit plans of the existing and the proposed drainage line/manhole position in relation to the building and proposed extension.

Check your water supplier's website or google the supplier + buildover agreement. Different suppliers have different requirements. Thames Water would not let you have an internal manhole - they require you to remove the manhole, replace it with pipe and provide a different access point for rodding outside of the building's new footprint. It was all pretty easy as long as you read the supplier's requirements carefully and make sure you comply.

Good luck!

Helpful information. Sorry OP about my curt place marking post, I was in a hurry.

we have just moved one for a new extension - we had planning permission and it was mentioned on there but the builders have just moved it - don't think they have told the water company so looks like I'd better check if they should have?

We had to get a drain survey and permission from the water company. There was nearby access from our neighbours gardens to the drains so it wasn't an issue. Our extension was built over it.