Can You Build Foundations Over a Drain?

Can I put foundations over drains?

The answer to this question is ‘it depends’. Every building project is different, so it may be worthwhile getting external advice from those in your local area, such as planning councils and local authorities. Generally, it is not recommended that you put foundations over a drain, particularly in domestic areas. Building over or near drains can cause serious structural and safety issues as well as disruption to the water flow and lead to odour nuisances and environmental damage.

Are there instances where I cannot build over a sewer?

Yes, there are instances where building over a sewer is not only not advised - it may even be illegal. If you are considering building over or near a public sewer you will need to obtain permission from your local Water Authority. Even if they approve the work, it is likely that they will require you to pay a fee and carry out work to their specifications.

In addition, there may also be restrictions when it comes to private sewers. For instance, your local planning department may have restrictions on how close a building can be to a private sewer pipe in order to ensure it is not disturbed during any potential building works. 

Do you need planning permission to build over a drain?

Yes, you may need to seek planning permission if you are wanting to build over a drain pipe on your property. Again, this will depend on whether the pipe is a public or private one and the exact location of the pipe. This is because permissions are required to ensure that construction works do not damage the pipe and that any potential disturbance to the water table is kept to a minimum. 

How close can foundations be to a private drain?

The exact distance a foundation can be from a private drain will depend upon the type of drain and the surrounding area. Generally speaking though, foundations should be at least 3 metres away from any sewer or drainage pipes and preferably more if the local environment allows for it. Any closer than this and you could risk disturbing the water table and damaging the pipe.  

How to build over a private sewer pipe in the UK?

If you do need to build over a private sewer pipe, it is essential you follow the correct procedures. The first step is to contact your local Water Authority who can advise on the necessary steps that need to be taken in order to get approval for the project. These steps may include obtaining a ‘Build Over Agreement’ which is a document that outlines the requirements of the Water Authority in order to protect the public and the environment. 

It is also important to note that any building works over a private sewer pipe must be carried out with the full permission of the owners of the pipe, who should also be consulted throughout the entire process. It is possible to apply for a 'Build Over Consent' which allows works to proceed over a pipe. This application must be sent to both the Water Authority and the owner of the pipe and both parties must agree before any building work can begin. 

In conclusion, while it is possible to build over a drain, it is important to take all necessary precautions and follow the right steps to ensure the safety and security of the environment and that any potential disturbance to the water table is kept to a minimum.