House extension built over drains - help!

debbiermcd

Hi,

Need to know urgently how we find out where we would stand legally if a house extension was built over drains which we're told are shared by 6 houses in a row became blocked or damaged?

We've been advised it's against regulations but that people do it anyway so it's more of a grey area.

If the extension exists and something was to go wrong with a drain managed by a local authority can they force us to make access available even if this meant uplifting a floor?

Didn't require planning permission re size and has been certified by an architect yet a second architect says it could be a problem in the future.

Any advice?

Thanks, D

BE_MIEI

debbiermcd wrote: »

Hi,

Need to know urgently how we find out where we would stand legally if a house extension was built over drains which we're told are shared by 6 houses in a row became blocked or damaged?

We've been advised it's against regulations but that people do it anyway so it's more of a grey area.

If the extension exists and something was to go wrong with a drain managed by a local authority can they force us to make access available even if this meant uplifting a floor?

Didn't require planning permission re size and has been certified by an architect yet a second architect says it could be a problem in the future.

Any advice?

Thanks, D

Firstly, I'm not a legal expert, but it looks to me as though your architect has wrongly certified that the building was constructed in compliance with the appropriate building regulations. Architects PI could be exposed. Seek proper legal advice.

sydthebeat

perhaps you'd like to offer why you think the pi is exposed?

DOCARCH

All depends whether or not the drains/sewers are private or public?

It does not really matter how many houses the drain serves, if it is private, there is no specific regulation to say that you cannot build over it.

If, however, the drain is public (i.e. the local authority own the pipe) then it is illeagal (usually) to build over the sewer (without the prior consent of the local authority) - exempt development or not.

Easy way to find out is to contact the local authority and ask for a copy/extract of the drainage map for your area/road/street. Only public drainage will show up on that map.

BE_MIEI

sydthebeat wrote: »

perhaps you'd like to offer why you think the pi is exposed?

For the reason I outlined, I don't really understand the question.

sydthebeat

BE_MIEI wrote: »

sydthebeat wrote: »

perhaps you'd like to offer why you think the pi is exposed?

For the reason I outlined, I don't really understand the question.

I suppose you haven't stated what regulations the architect could fall foul of. Local bye laws?

BE_MIEI

sydthebeat wrote: »

I suppose you haven't stated what regulations the architect could fall foul of. Local bye laws?

Well, if the drain is damaged as a result of the construction of the new extension and it results in an escape of water claim on a home insurance policy. The insurance company, following settlement of the claim, will undoubtedly seek recovery from the responsible architect who should have appropriate PI cover.

JustAThought

There are regulations against it.

You have to have drains moved : you cannot build over them.

Down to FLAC & get some proper free legal advise . Looks like that architect is in big trouble :0

DOCARCH

JustAThought wrote: »

There are regulations against it.
You have to have drains moved : you cannot build over them.

Not true!!!

sydthebeat

Im still waiting for someone to link to a regulation to state that an 'exempted extension' looses its exempt status due to being built over a public sewer...

im genuinely interested as its not something ive come across before... thus i ask has it got to do with local bye laws or what?

sinnerboy

BE_MIEI wrote: »

your architect has wrongly certified that the building was constructed in compliance with the appropriate building regulations.

JustAThought wrote: »

There are regulations against it.

What regulations exactly ?
TGD item ref or SI paragraph ref or bye law ref. please.

martinn123

sinnerboy wrote: »

What regulations exactly ?
TGD item ref or SI paragraph ref or bye law ref. please.

Don't think you will get an answer to that, in my experience you can build over a main line, provided its properly bridged, in that the walls do not impact down on the line causing damage, now or in the future.
A Structural Engineer will specify for example, a concrete lintel with blocks either side, on concrete, forming a bridge, on which the walls will be built, provided the line is not too close to the surface. But remember you break it, you dig it all up and repair.

however access becomes an issue if there is a manhole, where you want to build, in this case you approach the LA, and they say NO!

Access in the event of a blockage, anywhere on the line, is via the manhole.

Poor Uncle Tom

I think the mix up here may be coming from the notion of 'implied right of way' or 'implied leaway' which is a very different situation from what is being discussed here.

In my opinion, as martinn123 states it is possible to build up to, or in fact over, a main drain subject to normal precautions. But where there is a leaway or a right-of-way involved for the main sewer, there is usually a lane of sterilization involved where no building works can be carried out. If this is the case a quick call to your solicitor will clear it up as it will be mentioned in your deeds.

BE_MIEI

sinnerboy wrote: »

What regulations exactly ?
TGD item ref or SI paragraph ref or bye law ref. please.

If we refer back to the original post. The question related to the drain becoming damaged or blocked. If we ignore blockages, as blockages can be cleared via the manhole as mentioned in a previous post. Then, if the drain becomes damaged due to applied loading from the building then by definition the building will have lost support due to the collapse of the drain. Therefore, it follows that the building was built on unsuitable ground i.e. over the pipe and the trench backfill material (made ground). You will find that the building regulations do not permit this. Refer to TGD-A.

Part 5 - Strip foundations of plain
concrete
Conditions relating to the Subsoil
1.1.5.1 There should not be -
(a) made ground or wide variation in type of subsoil
within the loaded area, or
(b) weaker type of soil at such a depth below the
soil on which the foundation rests as could
impair the stability of the structure.

dinglebay

From TGD H, Drainage and Waste Water


1.1 GENERAL
1.1.1 Guidance
1.1.1.1 This Section of the Document gives
some guidance on good practice in relation to
noncomplex drainage systems.

Where a building is being extended and the
extension is to be built over or in close
proximity to a drain / combined drain, the
work should be carried out without
endangering the integrity of the drain or
limiting access to the drain for the purposes
of inspection or maintenance. Where the
drain serves two or more dwellings /
properties, (combined drain), the local
authority should be consulted.


In my experience, generally achieved by encasing pipe where it runs under the structure, and lintels over where it runs under a wall.

If I'm wrong, both myself and the many Engineers who have designed/specified such details for me are screwed !!

but I don't think so.

jsn.peters

Tough one hope it works out for you

sinnerboy

debbiermcd wrote: »

Hi,

Need to know urgently how we find out where we would stand legally if a house extension was built over drains which we're told are shared by 6 houses in a row became blocked or damaged?

Are you looking to buy a house and so this is all "what if" ?

Or are are you ( without seeking too much detail from you of course ) facing an actual problem ?

leeomurchu

Could you not create a new access to the drain beside the extension and point out that you moved the access/manhole out from under the planned extension.

I was always of the opinion that covering over access to a drain is a big no no and if it's picking up 6 other houses I doubt it's private.

Worst case scenario I guess they could ask you to lift the floor for access but I'm surprised this wasn't picked up by whoever designed the extension and I wonder if this brings up another issue with Planning Permission for the extension?

I stand to be corrected on all these points as they're my thoughts only no facts more of an interest in this topic though.

sinnerboy

BE_MIEI wrote: »

If we refer back to the original post. The question related to the drain becoming damaged or blocked. If we ignore blockages, as blockages can be cleared via the manhole as mentioned in a previous post. Then, if the drain becomes damaged due to applied loading from the building then by definition the building will have lost support due to the collapse of the drain. Therefore, it follows that the building was built on unsuitable ground i.e. over the pipe and the trench backfill material (made ground). You will find that the building regulations do not permit this. Refer to TGD-A.

Part 5 - Strip foundations of plain
concrete
Conditions relating to the Subsoil
1.1.5.1 There should not be -
(a) made ground or wide variation in type of subsoil
within the loaded area, or
(b) weaker type of soil at such a depth below the
soil on which the foundation rests as could
impair the stability of the structure.

So that's a no then.

I note someone ( dinglebay ) has posted text from a TGD which expressly , if conditionally , provides FOR building over drains.

BE_MIEI

sinnerboy wrote: »

So that's a no then.

I note someone ( dinglebay ) has posted text from a TGD which expressly , if conditionally , provides FOR building over drains.

Buildings are built over drains all the time. Buildings can never be supported on drains. I'm astonished that you cannot seem to appreciate the difference.

sinnerboy

Thanks for clarifying . :-)

sydthebeat

BE_MIEI wrote: »

Buildings are built over drains all the time. Buildings can never be supported on drains. I'm astonished that you cannot seem to appreciate the difference.

hummm, a MIEI with no grasp of force displacement,???

does that mean my gable wall is supported on the ground floor wc window??

actually, does that mean that every toilet waste pipe exiting a wall is bound to fault?

BE_MIEI

sydthebeat wrote: »

hummm, a MIEI with no grasp of force displacement,???

does that mean my gable wall is supported on the ground floor wc window??

actually, does that mean that every toilet waste pipe exiting a wall is bound to fault?

If you knew anything about construction, you would know that your gable wall was constructed before your wc window was installed. Therefore it follows that the wall is not supported by the window. Similarly, an opening was made in your wall before the wc pipe was installed, therefore the wall is not applying load to the pipe. I'm amazed that you consider yourself qualified to discuss these subjects with any level of authority.

Also, you are fooling nobody with pseudo scientific rubbish such as "force displacement".

Poor Uncle Tom

Stop the sniping, please.