Building over or close to Severn Trent sewer pipes

How to get permission for a home extension to be built over, or within 3 metres of, our sewers.

Check sewer maps first

While homeowners and tenants are responsible for private drains, we’re responsible for public sewers. Sometimes, our sewers run through or close to private properties.

If you’re thinking about extending your home, or adding a conservatory or garage, you should check our sewer network map to see if your building work is close to any of our assets. Please note, this will incur a small non-refundable fee and the records are furnished as a guide only, with it recommended to verify accuracy on site. Please do not hesitate to contact us, if you have any enquiries prior to purchasing a set of plans.

You must let us know if the building work is planned to go over or within our protective strips identified below.

Protective Strips Based on Pipe Diameter :

Please contact us at the earliest opportunity, in the event of your proposed works encroach the above protection zones.

Note : This process is designed to assist existing homeowners, extend their homes over our small diameter sewers. Therefore, if you are constructing a new home or unattached extension, then please complete the new waste or waste diversion application.

Before you begin any work

Sewers are often located within private properties and sometimes near buildings.
Building works can affect these sewers.
It's crucial to ensure they're not damaged and remain accessible for future maintenance.

Extending your house, building a conservatory, garage, or basement/cellar can impact underground sewer pipes.
If you plan to build over or near a public sewer, permission is mandatory before starting work.

Permission and approval

Your building work may need planning permission or building regulations approval from the local authority and your water company’s approval.

Some work falls under homeowners’ permitted development rights or may not require Building Regulations approval, for project such as:

conservatories
car ports
porches

However, planning permission and building regulations approval do not give you automatic permission to build over, or close to, our sewers.

We have a building over team and approval process in place, where we will work with you to ensure your development can go ahead, while at the same time making sure both your property and our sewers are protected.

Application forms

There are two application forms. You should only need to use one of them. Make sure you complete and submit the right one for your project.

Please note: using the incorrect application form could delay your application process.

You’ll need a formal build over agreement if any of the building work is:

using pipes up to 225mm in diameter
over or close to sewers 300mm diameter or greater (please contact us for guidance prior to making an application)
over or close to a pressurised sewer (please contact us for guidance prior to making an application)
over or close to a pitch fibre pipe (material)
on manholes, inspection chambers or rodding eyes within or nearby your extension
on sewers with a Legal Easement (this may be identified within your property Deeds)
using a raft or piled foundation

If you’re building over a sewer, you’ll need to tell us if you’re going to replace the pipe or provide a CCTV survey showing that you don’t need to.

You only need to use the self-certification application form if the building work:

is an extension to a single domestic property
will use pipes up to and including 150mm diameter
does not require connections or manhole relocating outside the extension (Formal Agreement required)

Charges

There are 3 different pay structures; the application fee is dependent on the nature of the public sewer or type of development.

Formal agreement	Class 1	Up to and including 150mm sewers	£170
Self-certification	Class 2	225mm sewers	£195
	-	-	£65.00

You should send your completed application to our Building Over Team.

We’ll check your proposed building work doesn’t adversely affect your property or our sewers.

Once your application and payment have been received, we’ll aim to let you know if it has been successful in 10 working days.

If it’s not successful we’ll let you know why and tell you what you need to do to get an approval. Unfortunately, at times there is no solution, and we’ll talk through site specifics if that becomes the case.

Contact our team

The Building-Over team helps residential developers to understand and plan what needs to be done when working near our pipes and manholes.