Design Approval Process

New water mains for your development can be laid by us or you can use your own contractor, also known as a Self-Lay Provider (SLP). Once your development is complete we will adopt the water network. 

Since January 2022 we have allowed Self-Lay Providers to complete some connections to our existing water network where no new mains are being laid.


Self-Lay Providers must be accredited to the Water Industry Registration Scheme (WIRS) which is run by Lloyd's Register. Being accredited means they work to national industry standards, so they understand our policies and procedures for laying new mains and making service connections.


You can find a WIRS accredited company, and information on the scheme, on the Lloyd's Register website.


Below is a guide for working with self-lay providers, including links to relevant application forms. For all correspondence relating to self-lay works, including application forms, please send to:

Please note that whenever you make a connection to our water network you must call our control room on 0345 672 3723 to let them know before and after the work is carried out.


Self Lay Calculator

Get an approximate cost for the work you are carrying out with our
self-lay calculator.

  • As a developer, before you apply for planning permission, it’s important to understand any potential challenges with supplying water to the site. We provide a free pre-planning assessment, to do this we’ll need information on your development.

    Please complete a Water pre-development enquiry form (PDF 238 KB opens new window) and return to us with:

    • A map showing the site boundary and preferred point of connection or site entrance.
    • The estimated date the water supply is required.
  • At the detailed planning stage, please complete a Self-lay point of connection application form (PDF 178 KB opens in new window), you will need to include:

    • Planning status and reference number.
    • Estimated build programme.
    • Access or third party land requirements.
    • Site layout plan.

    You can also work out approximate costs for the work with the self-lay calculator.

  • For your water network designs to be approved please complete the Self-lay application form (PDF 332 KB opens new window). For details of our charges, please see the New connections and developer services charges scheme (PDF 2.36 MB opens new window).

    You will also need to provide:

    • Most recent site layout in CAD format. 
    • Proposed water network design (CAD and PDF format).
    • A completed United Utilities’ risk assessment for water pipes Land risk assessment (PDF 315 KB opens in a new window)
    • The estimated date the permanent water supply is required.
    • Confirmation of the lead designer for the development and a copy of HSE F10 form (if applicable).
    • Main contractor’s project health and safety plan.
    • Pre-remediation or post-remediation site investigation (SI) report (where applicable).
    • Easement drawing (CAD and PDF) (if applicable).
    • List of affected land owners (if applicable).

    For further information please see:

  • With our design acceptance we will also issue a self-lay agreement. All parties involved in the development should sign the adoption agreement before sending it to us, we will then sign it. 

    We will then send details of any construction costs and infrastructure charges. For sites with multiple plots, we will also email a tracker form to the SLP, this is a list of all plots and their status.

  • Complete a whereabouts form with details of the work being carried out near our water network and send to us. 

    It’s then over to you to construct the mains as per the agreed design.

    If your site is covered under our old terms, the branch connection will need to be made by us. When you’re ready for this, please let us know a minimum of 28 days before by completing the Request for work (RFW2) for mains branch connections to an existing water main (PDF 138 KB opens in new window).

    If your self-lay application was made after 1st January 2021 then the branch connection may be considered as contestable work therefore: 

    If the SLP is making the branch connection then a request for permission to work form must be completed and sent to us a minimum of 5 days before your intended connection date for our approval. The connection should be carried out on the agreed date and you should then confirm within one calendar day that the connection went ahead as planned, and within 5 days submit your completed connection form for us to review.

    Please note that whenever you make a connection to our water network you must call our control room on 0345 672 3723 to let them know before and after the work is carried out.

    If the branch connection is being made by us, we will make the connection in line with the date agreed in your signed water adoption agreement. Please note that this will be a minimum of 28 days after you return your signed agreement, acceptance note, payment to us and request for work (RFW2) form to us.

  • Before the new main can be connected, it needs to be pressure tested and samples taken for bacteriological testing, please let us know five days before the work is carried out by completing a Mains testing and service connections programme form (SL07) (Excel 31KB).

    Once you receive valid pass sample results, please send the information below to us within one calendar day of receiving the results:

    • If the SLP is accredited for the construction of routine mains connections, please submit a request for permission to work form. We will give our permission within seven calendar days for the mains connection to be made. It should be carried out on the agreed date and you should then confirm within one day that the connection went ahead as planned.


    You should also supply:

    • Pressure and sample result certificates.
    • Completed vesting certificate, including notification of plots for connection (copy of certificate is included with adoption agreement). 
    • As-laid drawings.
    • Proposed date for works via the weekly whereabouts form.

    Following the main's connection taking place, we will issue the declaration of vesting. The mains will then be part of our water network which we are responsible for.

  • If you want us to make the connection please complete a Request for work (service connection) RFW1 form (PDF 253 KB opens new window).

    Please also provide:

    • Written confirmation of the new postal address for each plot from the local authority street name and numbering department, or confirmation that they’re showing on the Royal Mail website.
    • WIAPS (Water Industry Approved Plumber Scheme) certificate for pipework if you’ve used a WIAPS certified plumber, if not please arrange an inspection by us.

    Alternatively the SLP can make the connections. Where the connection is being made to the newly laid mains then notification of intention to connect (at a plot level) should be sent to us via the weekly whereabouts form, along with postal addresses from the local authority street name and numbering department. If the connection is being made to an existing main then a request for permission to work form should also be sent to us no less than 5 working days before you intend to make the connections for approval. The SLP can then carry out the connection and fit the meter (where applicable).

    Please note that whenever you make a connection to our water network you must call our control room on 0345 672 3723 to let them know before and after the work is carried out.

  • Once the connection has been made the SLP should notify us, via their tracker, which plots have been connected, the date of the connection, and the meter serial number.

    Guidance on metering including reporting serial numbers, tagging and our meter location policy can be found in our Meter Guide for SLP’s.

    Alternatively, if we are fitting the meter, we will contact you to arrange a time to do this.

    We will then register the connection and meter on our billing system.

For further information please see:

Codes for adoption 

In January 2021 Ofwat introduced a new standard practice across the water industry in England for water companies to follow when adopting self-laid mains.

This standard practice is known as the code for adoption and also referred to as "the codes".

For further information please see the Water UK approved documents.