HV Electrical Design
DNO · IDNO · Infrastructure

Precision
Engineering for
Critical Grid
Infrastructure

Specialist high voltage electrical design for DNOs, IDNOs, and infrastructure developers. 33/11kV primary substations, complex cable schemes, and full DNO submission packages — delivered with technical rigour, no layers.

Current Status
Active & Delivering
33/11kV DesignExpert
DNO SubmissionsExpert
HV Cable DesignExpert
FEED & FeasibilityAdvanced
SSEN G99 ENA IFC CPO BNG ED2 Active ED3 Ready
Trusted Partners
M-PE Partner TBC Partner TBC
Services

HV Design Services

End-to-end high voltage design — from feasibility through to IFC packages and full DNO submission.

01

33/11kV Substation Design

New-build and refurbishment primary substation design from concept to IFC — SLDs, equipment schedules, GA drawings, full design packages.

02

HV Cable Design

33kV and 11kV underground cable route design — cable sizing, thermal ratings, joint bay positioning, and detailed cable schedules.

03

DNO Submission Packages

Complete Part A and Part B design packages for DNO and IDNO projects — all drawings, schedules, and supporting documentation.

04

FEED & Feasibility

Front-end engineering studies — options appraisals, technical constraint reviews, and preliminary scope definition for HV infrastructure.

05

CAD & Drawing Production

High-quality CAD deliverables — SLDs, GA drawings, cable route plans, and as-built records to client and DNO standards.

06

Technical Advisory

Independent technical review, design assurance, and advisory support for developers, contractors, and asset owners on HV infrastructure.

Platform

Engineering Tools & Products

RDE is building a suite of engineering tools and digital products alongside its consultancy work. Each tool is purpose-built for HV and LV design professionals — more launching as the ED2 programme continues and ED3 approaches.

Resources

Technical Documents & Guides

Practical HV engineering reference material in development — technical packs and guides built for DNO and infrastructure professionals. Coming soon.

DNO Submission Checklist

A practical Part A/B submission checklist covering typical DNO drawing and documentation requirements.

Coming Soon

33/11kV Substation Design Guide

A comprehensive technical reference for primary substation design — SLD structure, equipment specification, and IFC deliverables.

Coming Soon

HV Cable Sizing Reference Pack

Cable sizing methodology, thermal rating worked examples, and route design considerations for 11kV and 33kV underground schemes.

Coming Soon

More packs in preparation

Additional technical guides and reference packs are being developed. Register interest to be notified on launch.

Coming Soon
About

Built for Serious HV Engineering

Randall Design & Engineering is an independent HV electrical design consultancy operating across the UK. Deep DNO framework knowledge, hands-on design delivery, and a curated associate network.

Actively delivering complex HV projects through RIIO-ED2, while building the capacity model and service structure to meet the demands of the upcoming ED3 investment period.

Hands-on Technical Lead

Direct delivery. No layers between the brief and the engineer doing the work.

Curated Associate Network

Scalable specialist capacity without compromising on quality or technical oversight.

Delivering in ED2 · Building for ED3

Active RIIO-ED2 delivery across complex HV programmes, with a service model being shaped now for the scale of ED3.

Engineering Credentials
33kV
Primary voltage expertise · SSEN & multi-DNO
ED2 Active ED3 Ready DNO Submissions CPO Projects IFC Packages G99 ENA Standards SHET Interface BNG / NNL Part A / Part B UK-wide
Contact

Start a Conversation

Whether you have a live project, need capacity support, or want to understand how RDE fits into your delivery framework — get in touch directly.

Phone+44 7356 253 540
LocationSouth of England · operating UK-wide
HoursMon–Fri, 08:00–17:30