Building over a sewer: Full Application


If you’re extending your property, you’ll need to make sure you know if there are any water mains, public sewers or drains on your land. It’s a good idea to find out before you begin, so the work goes as smoothly as possible.

We’d advise all our customers to complete the self-certification form first.

If you have already completed the form and don’t meet our criteria, then you need to fill in this full application, which is a more detailed form.

Once you’ve filled in the full application, we may either give you permission via a formal consent letter, or we’ll grant permissions via a legal contract. In both cases our team will be in touch to explain.

How long will it take?

  • Once we've received your application, we'll aim to respond to you within 14 working days
  • In some cases, we may need further information from you before being able to decide if the project can go ahead, or if your proposals need to be altered to ensure the sewer can be protected
  • To avoid delays, it’s important that you submit all the requested information

It’s worth noting that to complete the below form, you will need to provide:

  • Location plan at a scale of 1:500 - Please mark up the plan as follows: Property boundary edged green, extension shaded pink, public sewer in red
  • Dimensioned existing and proposed plan accurately confirming the position of the public sewer - These should clearly show the foundation type, internal diameter and material of the sewer
  • Drawings showing the relationship between the sewer and the new foundations - This should include the depth of the sewer and the new foundations
  • Are the Premises Freehold or Leasehold? - If the property is leasehold, approval cannot be given unless the freeholder enters into the agreement or provides written consent

Are you a customer in need of extra support?

If you’re converting or extending your property to make it more accessible for someone with physical impairments, then let us know on the ‘nature of proposal’ section of your application form. We can offer additional support such as helping you to fill in your application, and more advice and support through the building and construction process. To discuss your proposals please contact our dedicated Build Over Sewers team on 0800 917 2652.