Enquire to Build Over a Public Sewer

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.

Watch our video to find out what you need to do before starting any work. You can find more information below as well as a form to apply.

Working near our pipes

This video explains what to consider before you start any building work on your new project.

See our property searches to search maps which show the location of our pipes. We have information on what to do when working near our pipes which you can read here.

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 (PDF 928 KB opens in a new window) will give you all help you need to complete the enquiry form.

Download the Declaration of works guide and form (PDF 593 KB opens in a new window).

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

  • 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' (PDF 928 KB opens in a new window). This should be sent to WastewaterDeveloperServices@uuplc.co.uk

  • We would prefer that you didn’t build over any sewers/drains, and in many cases a sewer diversion is preferable. You need permission to divert a public sewer and more information, including an enquiry form can be found on our website https://www.unitedutilities.com/builders-developers/wastewater-services/sewer-diversions/diverting-a-sewer/

    Where the option to divert the sewer is not feasible, we will consider entering into a ‘Build Over Agreement’ if you meet all of the required criteria. You will need to submit an enquiry form to us and we will assess your application. The ‘Build Over Agreement’ is a legal document which is put in place to protect the sewer/drain and makes sure that we can still access the pipe if something goes wrong.

    In some circumstances, we may issue a retrospective BOA if work has already been carried out over, or close to, a public sewer. This is by exception only.

  • Where your proposed build is deemed as relatively low risk, this may fall into the ‘Protocol’ agreement that United Utilities has with the majority of LABC’s across our region. For more information please read our ‘Declaration of Works’ document here which outlines how the ‘Protocol’ works. 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.

  • 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.

  • 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.

  • 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.

  • We will not agree to the following being built over:

    • Pumping/Rising mains
    • CSO’s
    • Outfalls
    • Manholes or access points
    • Most brick, masonry or pitch fibre sewers
    • Strategic Sewers (usually large diameter, deep sewers)
    • Water Mains
    • We will not allow new residential properties or extensions of industrial and commercial properties to be built over our sewers