Top of main content

Developing over or near sewers

We’re responsible for taking care of our sewerage network in line with Section 94 of the Water Industry Act 1991. 

It may not be permitted to construct new properties over sewers or drains, we would prefer that the public sewer be diverted if possible. Find out more about diverting a sewer.

Build over agreements are required for any building works to existing properties within 3 metres of a public sewer, or within 1 metre of a public lateral drain. This is to prevent damage to the sewer network, and ensures we have suitable and safe access to carry out maintenance and repairs.

For more information about build over agreements, please see our build over technical specifications.

Apply to develop over a sewer

 Apply now


If you're building over a sewer with the internal diameter of 375mm, it's likely to be considered a class 3 application. Below you'll find some helpful frequently asked questions about class 3 build over applications.