Building over an Access/Inspection chamber

[Spinny]

Please can anyone advise on building over a domestic drainage access/inspection chamber ?

Is this permitted by building regulations ?

 

(My neighbour has advised he plans to build an extension over the access/inspection chamber for his drain and install a floor hatch for access. (Sub floor void likely to be 60-75cm). This drain then crosses the boundary to join our drain and therefore as I understand it becomes a public drain at that point.)

[Mr Punter]

They will need to retain the access / inspection chamber or make alternative access / inspection points.

[JuddlyFire]

Buildings or extensions should not be constructed over a manhole or inspection chamber or other access fitting on any sewer (serving more than one property) (Document G, Section Index, paragraph 1.3, page 808)↗. Approved Document H1 Section 2, paragraph 2.53 provides that access points to sewers (serving more than one property) should be in places where they are accessible and apparent for use in an emergency (Document G, Section Index, paragraph 1.3, page 808)↗.

If an extension is to be constructed, the access/inspection chamber must be retained or alternative access/inspection points made, as indicated in the requirement that buildings and extensions should not be located where they would remove such a provision where this already exists, unless an alternative access point can be provided on the line of the sewer at a location acceptable to the owner (i.e. the sewerage undertaker in the case of a public sewer) (Document G, Section Index, paragraph 1.3, page 808)↗.

Note that the drain in question becomes a public drain once it crosses the boundary and joins the neighbor's drain, so it would be subject to the regulations regarding public sewers.

The_Merged_Approved_Documents_Oct24.pdf

[Conor]

He'll have to move it.

[Spinny]

The neighbour's drain does not 'serve' my property, rather the neighbour's drain exits the inspection chamber at the side of his property then crosses the boundary and feeds into the inspection chamber on my property. My drain also feeds into the inspection chamber on my property. The inspection chamber on my property is then connected onwards to flow into the main sewer serving the houses on my side of the street.

 

So unless there is some special meaning to the word serve, it would seem the inspection chamber on my property and the pipe that crosses the boundary onto my land to connect to it  'serves' his property.

 

Therefore it seems he can build over it ?  He says he will retain access to it via a hatch in the floor above it.

 

Am I missing something ?

 

Edited 17 hours ago by Spinny

[Spinny]

Also note that none of these drains are shown on the 'sewer map' held by the local sewer company. Their map only shows the main sewer and does not show any of the chambers and pipework that connect all the properties to the main sewer. When I last spoke to the sewer company they said my chamber and the pipe to the boundary were indeed public sewers even though not shown on their map. Furthermore they said they did not need to be added to their map as all public sewers were their responsibility anyway. (Not sure now whether this might just be the sewer company avoiding extending their map ?)

 

This seems like a huge hole in the building regulations...?

(Is this really meant to mean you can do as you please with a drain/sewer not shown on a map - which presumably means millions around the country ?)

 

Quote

Requirement H4 applies only to work carried out: (a) over a drain, sewer or disposal main which is shown on any map of sewers; or (b) on any site or in such a manner as may result in interference with the use of, or obstruction of the access of any person to, any drain, sewer or disposal main which is shown on any map of sewers.

 

Edited 17 hours ago by Spinny

[Spinny]

Anyone know the answer here ?

 

Do building regulations not apply to drains on private properties (i.e.most/many houses) because they don't appear on 'sewer maps' ?

 

[Nickfromwales]

35 minutes ago, Spinny said:

Anyone know the answer here ?

 

Do building regulations not apply to drains on private properties (i.e.most/many houses) because they don't appear on 'sewer maps' ?

 

Ok. 
 

In reality, all you need to do is provide a rodding point outside of the footprint of the new build / founds, so you can through-rod it.

 

In terms of it getting blocked, any decent jetter will get in there and clean it out in an hour or less, and if its got no history of blocking I doubt there’s any real issue.

 

If it was my job I’d get a full camera inspection / video survey done before to look for crack / roots / imperfections that may cause problems downstream and get those sorted before covering it over. 
 

In honesty / actuality, I have zero idea why you care even slightly about this. It will not / cannot affect you in any way whatsoever, other than a jetter asking permission to open your manhole to be able to jet theirs in the event of a blockage occurring.

 

If it did block, it still wouldn’t affect you in terms of yours still functioning correctly.

[ProDave]

6 minutes ago, Nickfromwales said:

In honesty / actuality, I have zero idea why you care even slightly about this. It will not / cannot affect you in any way whatsoever, other than a jetter asking permission to open your manhole to be able to jet theirs in the event of a blockage occurring.

Is the OP looking for a way to block his neighbours extension from being built?

[Nickfromwales]

Just now, ProDave said:

Is the OP looking for a way to block his neighbours extension from being built?

Not my problem. Lots of odd balls out there tbf, and most would like to do something themselves with full and free rein, whilst then they’d object to others doing similar.

 

I’ll go make another coffee whilst the world continues about its business.   

[mjc55]

@Spinny What situation do you envisage that would be an issue to you?  Is there something particular that is worrying you?

[JuddlyFire]

The core regulation states: "Buildings or extensions should not be constructed over a manhole or inspection chamber or other access fitting on any sewer (serving more than one property)." (Document G, Section Index, paragraph 1.3, page 808)↗ This is quite clear - you generally cannot build over these access points when they serve multiple properties.

In this specific case, the critical question is whether the drain in question qualifies as a "sewer serving more than one property." Based on your description and diagram, since the neighbour's drain crosses the boundary and connects to your inspection chamber (which both properties feed into), this appears to be exactly the type of sewer the regulation is addressing yet the sewer company identifies the entire system as a public sewer (even if not on their map) conflicts with this interpretation. (Document G, Section Index, paragraph 1.3, page 808)↗

There's an important exception to note: "Buildings and extensions should not be located where they would remove such a provision where this already exists, unless an alternative access point can be provided on the line of the sewer at a location acceptable to the owner (i.e. the sewerage undertaker in the case of a public sewer)." (Document G, Section Index, paragraph 1.3, page 808)↗

This means:

• Simply installing a floor hatch (as your neighbour proposes) might be acceptable
• BUT it must be approved by the sewerage undertaker
• The alternative access must be "on the line of the sewer" and "acceptable to the owner"

Regarding your concern about maps: The regulations do state "These provisions apply to the construction, extension or underpinning of a building over or within 3m of the centreline of an existing drain, sewer or disposal main shown on the sewerage undertaker's sewer records..." (Document G, Section Index, paragraph 0.1, page 807)↗ However, the sewer company has already confirmed this is a public sewer despite not being on their map.

The key precedent here is that the sewer company has already stated these are public sewers. Their position carries significant weight in determining regulatory applicability. You should contact them directly with your neighbour's plans to get their official position.

I'd recommend your neighbour:

Formally consult the sewerage undertaker before proceeding (Document G, Section Index, paragraph 0.3, page 808)↗
Submit detailed plans showing how the floor hatch will provide adequate emergency access
Get written approval from the sewerage undertaker
Without this approval, building control would likely reject the plans since "Where it is proposed to construct a building over or near a drain or sewer shown on any map of sewers, the developer should consult the owner of the drain or sewer..." (Document G, Section Index, paragraph 0.3, page 808)↗ - and in this case, the sewer company has already established it's their responsibility.

This isn't a "huge hole" in the regulations - it's a situation where professional judgment from the sewerage undertaker is required, which is common in boundary drainage situations.

Source File: The_Merged_Approved_Documents_Oct24.pdf

[mjc55]

But at that point it isn't actually serving more than one property.  When the utility took over the maintenance of sewers on private land (was it early 2000's or early 2010's - I can't remember) the first in the line of drains remained private and only became public on the second property they served.