Building over a public sewer

iconPlease note our change of address for building over enquiries. So as not to cause you any delays, please send all applications to:

United Utilities Developer Services, Windermere House, 1st Floor, Lingley Mere Business Park, Lingley Green Avenue, Great Sankey, Warrington, WA53LP.

If you're planning any type of development, building something new or extending an existing building, you should check there’s nothing underground that could be affected i.e. water or wastewater pipes. Our property searches team can supply maps which show the location of our assets.

If you want to build over, or close to, one of our public sewers or lateral drains (this usually means within 3 metres), you need our approval, even if it is located on your land. We have to make sure that all of our pipes are protected from any potential damage that development may cause, so that they can continue to provide the service they're designed for. It's also really important that we can access our pipes for maintenance and repair.

If you need any more information, our Building Over a Public Sewer guide will give you all help you need to complete the enquiry form.

Download the Declaration of works guide and form.

For further information about building over a public sewer, contact us at wastewaterdeveloperservices@uuplc.co.uk

Working with building control bodies

During and after construction, a building control body is usually required to confirm that the work complies with national building standards (outlined in H4 Building Regulations). The developer can choose whether to use a Local Authority Building Control (LABC) department or an independent Approved Inspector to make this assessment.

We have made an agreement or ‘Protocol’ with a number of LABCs and Approved Inspectors, which gives them the authority to approve potential build overs on our behalf, so long as they meet specific criteria.

When a developer is working with building control, the inspector will review instances where a build over may be required. If they are satisfied with proposals and it fits our criteria, they will approve this on our behalf and the developer will not have to contact us for further approval.

If the proposed build over does not fit within our criteria, or the inspector has concerns with the proposals, they will escalate this to us so that we can talk to the developer directly to offer advice and agree next steps.

If you live in an area where the LABC does not use the Protocol (Cumbria, High Peak and Tameside) or if your Approved Inspector has not signed up to our Protocol, you should contact us directly using our ‘Build over enquiry form’. This should be sent to WastewaterDeveloperServices@uuplc.co.uk

Building over agreements

There are some circumstances when we will need to arrange a formal 'Building Over Agreement'. This is a legal document which is put in place to protect the sewer/drain and makes sure that we can access the pipe if something goes wrong. 

Any building control body working within our 'Protocol' will refer all instances of where a Building Over Agreement may be required by us for further investigation. In some circumstances, we may issue a retrospective Building Over Agreement if work has already been carried out over, or close to, a public sewer. This is by exception only.

Access points

We have to make sure that we can always access our pipes for necessary maintenance and/or repairs.

If we agree that you can build over a public sewer, you must make sure that you provide sufficient access points to the affected sewer (manholes and rodding points). Ideally, buildings and extensions should not be sited where they would remove an existing point of access. If this is not practical, we may agree to the re-location of an access point, outside of the proposed development. 

Access points should be easily accessible and visible for use in an emergency.

Further advice will be offered on access ponts when the development is inspected, either by us or one of our Protocol partners.

Approvals process

Any inspector who has reviewed a site on our behalf (either from a Local Authority or independent company) will advise us when inspections have taken place, and will also let us know the outcome, for example, if the build over is approved. 

The inspector will also tell us where the sewer/drain is located, as sometimes we may not have details of the pipes on our mapping systems. We will use this information to update the statutory sewer map.

If you go on to sell your property, we will know that the sewer/drain has been built over and that the work meets our approval. If requested, we will confirm this information to individuals or mortgage lenders acting on behalf of a potential buyer.

Possible issues with a build over

Any inspector who has reviewed a site on our behalf (either from a Local Authority or independent company) will tell us about developments that are outside of their authorised approval limits, i.e the building/extension is of a particular length or if the sewer/drain is particularly large or deep.

They will also let us know if they discover that the affected sewer/drain is in a poor condition or the ground conditions are unsatisfactory. If this happens we will arrange for one of our own inspectors to visit the site to advise on what should happen next. 

The most cost-effective solution for a pipe in poor condition is likely to be renewal of the pipe - the cost of which must be borne by the developer. If ground conditions are unsatisfactory, e.g. soils are easily eroded or contains fine silty sands, the developer will have to arrange for special design and construction plans to make sure that the pipe is protected from any risk of damage resulting from the development.