Developers and building

Whether you're building your own house, adding an extension or planning a big commercial development, we'll work with you to make sure your water and sewerage plans are right for your project.

Beach huts

Some changes to our Network Policy documents

As part of our annual review of design standards and network policies, we’ve made some changes to the following documents in consultation with our stakeholders: our Design and Construction Specification (DCS), Annual Contestability Summary (ACS) and Domestic Meter Location Policy.

Please find copies of the updated documents below. These policy documents have been published on 31 January 2023 to allow a 2-month period of notice before they come into effect from 1 April 2023.

Design and Construction Specification (v3)

Annual Contestability Summary (v3)

Domestic Meter Location Policy (v2)

Popular services

If you're planning a new building or extension, here's what you might need to look at:


If you're building or converting a property you'll need to apply for a new water connection.

Sewerage connection

You'll need a sewerage connection to take wastewater away from a new building.

Building over a public sewer

You'll need to apply for permission if there's a public sewer within 3 metres of your planned building.

Looking for something else?


Calculate your estimate

Get an estimate for a new or replacement water connection:​

  • it’s free​ to calculate
  • it takes less than 3 minutes​
  • you can calculate an estimate for up to three household water connections​
  • you’ll get a rough idea of the costs so you can decide what to do next.

This does not apply to large sites requiring new water mains or sewerage services.

Calculate your estimate


Mains scheme estimate calculator

Calculate a free estimate for works on a large development site, including new water main installations and individual plot connections. Ideal for professional developers and self-lay providers.

This is a .xlsx document which can be opened with Microsoft Excel.

Apply online

Our online forms are the best way to apply:

  • it’s quick and easy
  • you can pay by card
  • you can pay by BACS (bank transfer)
  • we’ll remember your details to make applying even easier next time
  • you’ll get an email confirmation when we’ve received your application
  • you can upload all your supporting documents.

Apply now

Unsure which developer service you need?

Whatever you're planning to build, we've created a guide to help you find what you need.

Services guide

All services

Apply online

Our online forms are the easiest way to submit and pay for your application.


If you're building or converting a property you'll need to apply for a new water connection.


Apply for permission to build over a public sewer or for a new sewerage connection.

New Appointments and Variations (NAVs)

Bulk water supply and sewerage services.

Level of Service

Our performance reports show the level of service you can expect from us.

Developer Services charges

Our services charging arrangements.

Environmental incentives and credits

See what discounts are available for sustainable developments.

Frequently asked questions

Everything you need to know about Developer Services.

Contact developer services

If you have a query or any feedback, please get in touch. We'd be happy to help.

Get in touch