Are you planning to build or extend your property over a sewer?

22nd May 2018

It is not uncommon for public sewers to be located within the boundaries of a property. If the plans for your extension build over, or near (within three metres) to a public sewer, certain permissions must be granted before the building work can go ahead.

Julie Tomasik, director and residential conveyancing lawyer at Ansons Solicitors in Cannock and Lichfield, Staffordshire, explains what you should do if you want to extend your property or erect an additional building onsite.

“It is vital that these permissions are obtained before any work takes place,” says Julie. “Building over or near to a sewer without having first obtained the relevant permissions comes with a number of serious consequences. It may be costly to rectify, it may cause problems when you come to sell the property and it may even result in legal action.”

What do I need to do? 

Extending or constructing a property will usually require planning permission or building regulations approval. While some developments are exempt from building regulations, all developments which are over or near to a public sewer will require permission from the water company.


There are two types of approval that can be granted:

  • self-certification approval; or
  • build-over agreement.

Firstly, if you are confident that your project will meet all the required conditions then you can obtain automatic approval; this is known as self-certification approval. If this is not the case a formal build-over agreement approval can be obtained.

In both cases the works will be inspected following completion to ensure that they have met a satisfactory standard. The different applications carry different costs, these can be found on the website of the local water board.

How do I know where the sewer pipes are located?

If you are unsure as to the locations of the sewer pipes there are two ways you can clarify this:

  • look for the inspection chambers, once these are identified you can ask a trained person, such as your builder, to open the chamber and identify the location of the sewer pipes; or
  • more accurately, you can arrange for a specialist to conduct a CCTV survey of the area, this will also indicate the condition of the pipes, which is an important consideration when building over or near to a sewer pipe.

What happens next?

Once any work is completed, the water authority will undertake a final inspection. If everything is satisfactory a final approval will be granted. This document is very important, and you should keep hold of this. You will need to provide it when you come to sell the property and it can cause a number of problems if you have misplaced it.

If you are thinking of buying or selling a house and are concerned about boundaries, please contact Julie Tomasik on 01543 267988, alternatively email or

The contents of this article are for the purposes of general awareness only.  They do not purport to constitute legal or professional advice.  The law may have changed since this article was published.  Readers should not act on the basis of the information included and should take appropriate professional advice upon their own particular circumstances.