Build over agreement rejected?

[SD73]

Hi all need some advice please!

We are looking to build a rear extension to replace our current rear extension, we have applied to Southern Water for the build over agreement as the extension will be over the top of the existing sewer manhole, which incidentally is about half a foot from our back door. The plan is to extend over this a couple of metres and move the access to a similar position adjacent to the new wall, however Southern Water have rejected this as they state it's within 4m of the sewer.

I am struggling to understand this as the current access is less than a foot from the current sewer but the the proposed would be similar?

Do I need to move this manhole 4m away from the property?

 

[Ivor Windybottom]

Are they worried about the pipe through your land, or a bigger sewer pipe that it connects into?

Do you have a diagram?

 

[jeds]

Very unusual, and an odd reason for rejection, since the very reason for the application is to build over a sewer?

I regularly deal with Severn Trent and Wessex and neither have any issue building over a sewer. Having said that, neither will allow a manhole inside the property and the minimum distance from any manhole to the sewer line is 500mm.

Is it a standard 100 - 150mm line?

 

[SpecialK]

Have they rejected it from building control writing to them with basic info? They normally do auto reject for anything complicated. If you ring them and provide some drawings you may be able to come up with a solution?

They rejected mine straight away as the footings where within 3m of the sewer. Once I had provided some drawings and promised to take the footings 150mm below invert they said it was fine.

 

[jeds]

That's a fair point. I presume you did provide buildover and technical details with your application?

 

[^woody^]

Cool story, but there is no details as to why the application was rejected.

 

[robinbanks]

Show us exactly what you sent to them (suitably redacted for personal info)

 

[SD73]

Sorry all, busy week after making this post I had an all nighter at work.

Ok so this is where the current manhole is

And I want to seal it and move it basically straight into the garden, as you can see they have dug down looking for the sewer pipe, we believe it's probably 2m deep.

Southern water have rejected saying we can't build within 4m of the sewer, but the sewer already runs under our building, so it makes zero sense?

The trench on the left of the pic is where we are extending to, and the pallets are covering the trench where we are extending out to, so the new manhole will be located a bit further into the garden than that with a new pipe running back to the existing location.

 

[SD73]

Oh and yes I submitted multiple pictures, architect drawings, structural engineer reports etc, building control sent everything across and I sent additional information after I done the application on Southern Water build over website. initially their response was that they was going to send a CCTV survey out, didn't hear anything for a week then this update that they have rejected it

"issue Notice of Rejection of Plans Reasons:
- No new foundation/building works over or close (within 4.0m) to the existing
public 175mm vitrified clay (VC) sewer critical by depth will be permitted.
Therefore, amend your plans to show the proposed foundations/walls should be
4.0m away from the existing public sewer/manhole."

 

[^woody^]

The 4m thing is nonsense as the requirement is not to load the pipework. Do your proposed foundations go down past the pipe invert level? I've had a quick look at the company web site and they don't mention the 4m criteria, so is something either not clear in the application, or have things been misinterpreted?

Normally if you design in accordance with Doc H, that's evidence of an acceptable proposal.

For the existing manhole, normally it would need to be removed and pipework adapted, not just covered over and sealed.

Post the drain layout and building footprint.

 

[jeds]

I've done hundreds of these and all of the water authorities I have ever dealt with - four I think, maybe five? - use a 3m criteria for building near. I've never come across 4m?

One reason for not allowing a build over is a critical or strategic sewer. I note Southern Water describe the line as 'critical' so this may be the problem? However, critical lines are normally 225mm or more? Again, I've never come across an issue building over a 6" line. In fact, most authorities have standing orders for lines up to 6" meaning you don't even need to apply if you can tick off certain criteria.

The normal procedure is to apply sending construction and technical build over details > the authority carries out a cctv survey, which is included in the application fee > they then either approve or tell you what they would prefer as an alternative.

 

[jono_h]

As Jeds says it’s usually 3m not 4m - confirmed on the Southern Water build over page.

Build over or near to a public sewer

If you are building a new property or extension you will need to ensure it does not affect our public sewer mains. Therefore, if your proposals mean building over/near (within 3 metres) a public sewer or lateral drain you will need our approval before doing so.

www.southernwater.co.uk

Have you checked the list to see if your proposal meets the requirements? And equally check the unacceptable list.

If you meet the requirements then just apply via the self-certification. I doubt a real person is even going to look at the application. I’ve just done mine with Welsh Water (who have near identical requirements) - filled out the self certification, paid my £81, got the acceptance email which I forwarded to my BCO and now I just have to build to Part H.

The only issue I can see, from what you’ve written, is that the foundations may need to be 150mm below invert; which if your sewer really is 2m deep is going to be expensive.

 

[SD73]

Ok sorry to bring this back up but this has been going on for weeks.

Here's the situation, We applied for a build over, we was unaware at the time that a sewer main runs through the back garden, it's approx 5m deep and 1.9m from the rear of our property.

SW were supposed to send a CCTV survey out but wanted us to wait 3 weeks so we got our own done and submitted it to them.

SW rejected our application initially because the manhole to the side of our property would be moved as it's going to be built over.

We redrew our plans and discussed with the builder and Southern Water that we could remove the manhole, fit a new pipe to the sewer pipe from the manhole with a rubber sleeve etc and have the new waste connect into that plus add a rodding point, and it seemed they were fine with that as our neighbours have a manhole.

However they then replied that they still won't agree as upon further inspection the sewer main in the garden is approx 5m deep and thus deemed "Critical by depth" and no building within 3m of this.

The survey shows the main being 1.9m in the garden, we had dug out footings, ironically right on top of this main!

So they are basically flat out refusing to let us build unless we divert the sewer main, which I estimate is going to cost more than the actual cost of the extension!

What's more annoying is a house further up the road has built their extension this year over the main and I think they just got retroactive permission.

Not sure how we move on from here, SW are refusing to allow us to continue, building consent can't happen without their say so.

Anyone have any advice or experience with this scenario?

I'm half tempted to just carry on with the build and seek retroactive permission but I'm not sure what the legal implications would be now that SW have already denied our application?

 

[noseall]

Ok sorry to bring this back up but this has been going on for weeks.

Here's the situation, We applied for a build over, we was unaware at the time that a sewer main runs through the back garden, it's approx 5m deep and 1.9m from the rear of our property.

SW were supposed to send a CCTV survey out but wanted us to wait 3 weeks so we got our own done and submitted it to them.

SW rejected our application initially because the manhole to the side of our property would be moved as it's going to be built over.

We redrew our plans and discussed with the builder and Southern Water that we could remove the manhole, fit a new pipe to the sewer pipe from the manhole with a rubber sleeve etc and have the new waste connect into that plus add a rodding point, and it seemed they were fine with that as our neighbours have a manhole.

However they then replied that they still won't agree as upon further inspection the sewer main in the garden is approx 5m deep and thus deemed "Critical by depth" and no building within 3m of this.

The survey shows the main being 1.9m in the garden, we had dug out footings, ironically right on top of this main!

So they are basically flat out refusing to let us build unless we divert the sewer main, which I estimate is going to cost more than the actual cost of the extension!

What's more annoying is a house further up the road has built their extension this year over the main and I think they just got retroactive permission.

Not sure how we move on from here, SW are refusing to allow us to continue, building consent can't happen without their say so.

Anyone have any advice or experience with this scenario?

I'm half tempted to just carry on with the build and seek retroactive permission but I'm not sure what the legal implications would be now that SW have already denied our application?

FIVE metres deep!! Fudginell, no wonder thy are concerned. That must be one heck of a trench.

 

[SD73]

Footings are the standard depth though but they flat out refuse to let you build within 3m of their 5m deep pipe, it's ridiculous really.