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Technical, policy & engineering documents

WPD has developed a Technical Information website specifically to provide detailed technical specifications and policy documents for connection providers working within the WPD area.

This website is continually updated with new and revised documents and registering for access to the site will also mean you are notified of these updates as they happen.

To request access to the site please follow this link.

To facilitate competition in certain areas of new connection work a number of documents have been developed. This relates to the following areas:-

  • Greenfield and brownfield low voltage housing estate underground networks and associated new, ground mounted HV/LV distribution substations;
  • Industrial & commercial connected loads up to and including HV (11kV);
  • Unmetered connections.

To assist Independent Connection Providers who may wish to compete in these areas, a suite of Ofgem national framework documents has been developed setting out common requirements for design and planning, material specification, and installation and records. Please click on the links below.

(Please note that the attachments on this page are large files, and may take a few minutes to load.)

For greenfield and brownfield LV housing development Installations:

Engineering recommendation G81 Part 1 - Design & planning
Engineering recommendation G81 Part 2 - Materials specification
Engineering recommendation G81 Part 3 - Installation & records

For industrial and commercial connected loads up to and including 11kV:

Engineering recommendation G81 Part 4 - Design & planning
Engineering recommendation G81 Part 5 - Materials specification 
Engineering recommendation G81 Part 6 - Installation & records

Each of these are required by Ofgem to be supplemented with local appendices. The WPD appendices must be read in conjunction with the national framework documents.

For greenfield and brownfield LV housing development installations:

WPD G81 - 1 Design framework appendix
WPD G81 - 2 Materials framework appendix
WPD G81 - 3 Installation and record requirements for LV housing developments

For industrial and commercial connected loads up to and including 11kV:

WPD G81 - 4 Design framework appendix
WPD G81 - 5 Materials framework appendix
WPD G81 - 6 Installation & records framework appendix

The former Central Networks was acquired by Western Power Distribution (WPD) in April 2011.  The above WPD G81 Appendices and processes will apply to future connections made in the former CN area with effect from 1 April 2012.  Customers making connections to the former CN systems should continue to adhere to the CN G81 Appendix:

  • For connections where a point of connection offer has already been provided
  • For connections where design approval has already been given by WPD
  • For connections planned to be made in the period up to 31 March 2012

Click here to see the CN G81 appendix.  This document will cease to have validity from 31 March 2012.

The following appendix applies to all types of connection:

WPD G81 Cable recording techniques framework appendix

A connection provider may provide diversionary or reinforcement work that is directly associated with a new or augmented connection at voltage levels not exceeding 33 kV.  The scope of such work is set out within a further national framework document.  Please click on the link below.

Engineering recommendation G81 Part 7 - Contestable diversionary and reinforcement underground and overhead work not exceeding 33 kV and HV/LV distribution substations.

WPD have a published set of Distribution Safety Rules (DSR's) which are in place for the protection of employees and the safety of all who may work on distribution network operator systems. 

A copy of the DSR's can be viewed here.