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Pre-Development Enquiry

Single Unit Developments

Application & Guidance

Assessment & Response

  • We will assess your application in detail.
  • Our response will outline the availability and capacity of our existing public sewer and water network.
  • Our response will also explain what we require from you at this stage.

Next Steps

Pre-Development Enquiry


Single Unit Pre-Development Enquiry (PDE) application needs to be submitted as soon as is practicable and prior to any formal planning submission.

Please ensure you complete all sections, in order to avoid delay or return of your application. Please refer to the guidance details below before completing your application form.

This form should only be used where you are proposing to construct a single house that requires a connection to NI Water’s Water/Wastewater infrastructure. A single unit PDE is not required for houses that require a water connection only.

The Pre-Development Enquiry Response will advise on the following:

  • Status of receiving Wastewater Treatment Works.
  • Current availability of water and sewerage infrastructure to accommodate proposedflows – foul, storm and water.
  • Proximity to Existing Assets within the site boundary (& referral to requiredassessment of protective measures).
  • Further requirement (as applicable) to apply for a Single Unit Impact Assessment.
  • Further requirement (as applicable) to apply for an Odour Assessment.
  • Further requirements (as applicable) to apply for a realignment of existing NIWInfrastructure.
  • Copy of NI Water Mapping records relevant to the site (Please note Disclaimer)

Single Unit Pre-Development Enquiry (SU-PDE) applications can be made to NIW to obtain information about the availability and capacity of water and sewerage infrastructure to service future development. NIW will advise if the existing infrastructure can accommodate the proposed development and provide detail on the anticipated points of connection. During a PDE assessment, NIW may identify potential capacity or odour issues which requires further analysis. As a result a further detailed assessment may be requested by NIW. This is known as a Single Unit Impact Assessment.

Note: NIW is committed to delivering new economic and housing growth, sustainably. In some cases, where our existing infrastructure is overloaded, NIW may have to refuse/defer new connections in order to protect the environment and our customers from flooding. The applicant will be notified of specific development constraints as part of the PDE process.

All applications MUST include the following:

  • A Site Location Plan 1:2500 map (LPS ACE map will suffice) with the site boundary clearly indicated in red and relative to an existing feature. Any other land owned bythe application should be shown with a blue line around its boundaries and if apublic right of way exists within or adjoining the site, it should be outlined in green.The 12-figure OS Grid Reference (x,y co-ordinates) of the approximate mid-point ofthe site is also required to allow the location to be assessed quickly and to avoidconfusion when viewing on our map server.
  • Planning references to all extant and live planning applications.
  • Extant Planning - if your site has extant planning and the approval date is morethan 5-years, you must provide a Certificate of Lawful Existing Use or Developmentto confirm that the planning is extant.

Returning completed forms

Please return completed form(s) by email to:

Email: developerservices[AT]niwater[DOT]com

Developer Services – Servicing Team

Northern Ireland Water Ballykeel Office

188 Larne Road


Co Antrim BT42 3HA

Tel: 03458 770 003

For more information on how NI Water lawfully processes personal data please view our Privacy Notice at;

Pre-Development Enquiry

Nominal Fee and response within 28 working days

We will review existing network and treatment capacity and the anticipated points of connection for water and sewerage services. We will also complete checks and advise of existing assets within the site boundary or if the site is within an odour boundary for one of our assets.

We will then provide a written response including a copy of our records adjacent to the site.

If there are no constraints you can then progress to make a formal planning application knowing that NI Water will be able to support your planning application and provide a positive response to your planning application

If there are constraints you will be asked to submit an Impact Assessment Application for Water, Wastewater or Odour and NIW will work with you to identify potential solutions. For site where we identified constraints NI Water will recommend to planners that the planning be refused until you have completed the necessary impact assessments and agreed a developer led solution for the capacity issues.

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