How to Become a CDAE or Lead CDAE on National Grid Projects (SR188.12)
Updated October 2026 using NG/ET/SR188, NG/ET/SR163 and the SR188.12 appointment form
If you want to know how to become a Contractor Design Approval Engineer (CDAE) or Lead CDAE on National Grid Electricity Transmission (NGET) projects, the first thing to understand is the level of accountability. The CDAE signs to confirm they have checked 100% of their discipline’s design before it goes to NGET. The Lead Contractor Design Approval Engineer (LCDAE) takes overall accountability for the contractor’s design process. Installation cannot start until NGET has accepted the design they have signed.
Both roles are appointed on the NG/ET/SR188.12 CDAE and LCDAE Appointment Form, and every nomination is checked by NGET before the individual is added to NGET’s master record. This guide covers:
- what the CDAE, LCDAE and Contractor Design Approval Engineer – Limited [CDAE (Limited)] roles are
- how they compare with design roles on other projects
- what SR188 and SR163 require of them
- the minimum prerequisites on the SR188.12 form
- the documents and competence check needed for appointment
- how to get the right training
Find about about National Grid CDAE / LCDAE Supplier Requirements Awareness Training from Pragmatic Here.
What is a CDAE?
The Contractor Design Approval Engineer (CDAE) and Lead Contractor Design Approval Engineer (LCDAE) roles are set out in National Grid Electricity Transmission (NGET) Supplier Requirement (SR) NG/ET/SR188 Design Management, with NG/ET/SR163 Management of Works covering how the design interfaces with construction.
A CDAE is appointed by the contractor for each Core Design Discipline on the project. SR188 defines five:
- Substation High Voltage (HV) Engineering: the primary design of the HV plant, layout, busbars, clearances and earthing
- Protection and Control (P&C) Engineering: the secondary design of protection, control, metering and auxiliary systems
- Substation Civil Engineering
- Overhead Line (OHL) Engineering
- High Voltage (HV) Cable Engineering
Within their discipline, the CDAE is responsible for making sure the design meets the Scope, is technically sound and complies with all relevant specifications. During delivery, they:
- complete their section of the Design Intent Document (DID)
- check 100% of the design and make sure it is error-free before submission
- sign the Design Compliance Audit Assurance Report (DCAAR) for each Design Package
- manage design changes through Design Change Notices, classifying each as minor or significant
- attend Design Review Meetings (DRMs) and Hazard Review Meetings (HRMs)
- make sure proposed plant and equipment is suitable and complies with National Grid (NG) Technical Specifications
What is a Lead CDAE?
The Lead Contractor Design Approval Engineer (LCDAE) takes overall accountability for the contractor’s design process. During delivery, they:
- lead and coordinate the contractor’s design team
- make sure the Design Programme is produced, maintained and implemented
- sign off the Design Intent Document and Technical Deviation Requests
- convene and chair Design Review Meetings
- make sure pre-construction hazard information is reflected in the design and the Construction Phase Plan
- coordinate interfacing packages and work by others
- run the design change management process
- make sure drawings follow SR135 Drawing Management
- keep the Principal Designer Representative (PD Rep) – Delivery updated with design progress, changes and documentation
- work with National Grid Electricity Transmission (NGET)’s Lead Design Assurance Engineer to resolve design issues
The LCDAE and Contractor Design Approval Engineer (CDAE) roles can be held by the same person at the same time. In practice, you typically cannot become an LCDAE unless you have already been a CDAE: the LCDAE needs to understand, from experience, what each CDAE is signing for.
CDAE (Limited)
Contractor Design Approval Engineer – Limited [CDAE (Limited)] is an authorisation with proportionately reduced competency requirements. It is used for simpler projects, such as multi-site or single-technology work where the design is repetitive or limited, and for specialist areas outside the Core Design Disciplines, such as tunnels or High Voltage Direct Current (HVDC). It covers a single discipline and is not transferable between projects. The status must be agreed with National Grid Electricity Transmission (NGET)’s Authorising Manager, Engineering Services, before the form is submitted.
A CDAE is more like a Checking and Approving Engineer with sign-off accountability
On many projects, a discipline lead checks the design and the client reviews it in detail. National Grid Electricity Transmission (NGET) works differently. SR188 assumes all aspects of the design are compliant unless proven otherwise. NGET’s Design Assurance Engineer (DAE) carries out a selective, risk-based audit, not a full check. The full check is the Contractor Design Approval Engineer (CDAE)’s responsibility.
| Typical construction project | National Grid (SR188) project | |
| Who checks the design | Discipline lead, with detailed client review | The Contractor Design Approval Engineer (CDAE) checks 100%; National Grid Electricity Transmission (NGET) audits selectively |
| Sign-off | Internal checking and approval | Contractor Design Approval Engineer (CDAE) signs the Design Compliance Audit Assurance Report (DCAAR) for each Design Package |
| Overall design accountability | Design Manager or Engineering Manager | Lead Contractor Design Approval Engineer (LCDAE) |
| Formal appointment | Usually internal | SR188.12 form, scored competency matrix and National Grid Electricity Transmission (NGET) competence check |
| Register | None | National Grid Electricity Transmission (NGET) master record of Contractor Design Approval Engineers (CDAEs) and Lead Contractor Design Approval Engineers (LCDAEs), not transferable between contractors |
The SR188 design process in brief
- Design Intent Document (DID): completed after contract award and approved by National Grid Electricity Transmission (NGET)’s Lead Design Assurance Engineer. DID Freeze takes place within 12 weeks of contract award unless agreed otherwise.
- Design Packages: the design is split into standalone packages, one per discipline, with references such as SUB-DP01, P&C-DP01, CE-DP01, OHL-DP01 and HVC-DP01.
- Design Programme: lists each package and its submission date, with enough time for assurance.
- Design Compliance Audit: every package is submitted with a signed Design Compliance Audit Assurance Report (DCAAR). NGET’s standard review time is 28 calendar days. Installation must not start until an accepted DCAAR is received.
- Independent check: Civil, Structural and Building Engineering packages need a full independent check by a chartered engineer (SR188.04).
- Design change control: minor changes can proceed unless NGET responds within 14 days; significant changes need a revised DCAAR.
- Technical Deviations: deviations from NGET Technical Specifications need a Technical Deviation Request (SR188.08) and Asset Manager approval. Type Registered equipment uses derogations under SR183 instead.
What SR163 adds for CDAEs and LCDAEs
NG/ET/SR163 Management of Works sets out how the design interfaces with construction:
- Duty holders: the contractor must appoint duty holders in line with SR141, SR188 or SR163 competency requirements, depending on their role.
- Changes of duty holder: National Grid Electricity Transmission (NGET) must be notified at least two weeks before a planned change of a named person, and a new appointment form completed. NGET can accept or reject the change.
- Design and Hazard Review Meetings: these must be held at regular intervals throughout the design, with a plan for managing residual risks through the life of the asset.
- Procurement and Type Registration: the Procurement Plan, due within 12 weeks of the Contract Date, must show that Plant and Materials conform to NGET specifications, including Type Registration.
- High Voltage coordination: the contractor must create or update stage-by-stage drawings to support NGET’s outage planning (STCP19-2).
- Temporary Works: Temporary Works must comply with British Standard (BS) 5975 and be coordinated with the permanent works design.
- Buried earthing: earthing systems must not be cut, moved or disturbed without consulting a competent designer and getting NGET’s prior agreement.
- Scaffold guards: scaffold guards and power line crossings must be designed to maintain the safety clearances in ENATS 43-8 and the National Grid Safety Rules.
SR188.12 minimum prerequisites
The SR188.12 form lists the following minimum requirements for all roles. Evidence of training or assessment, with completion and expiry dates, must be provided for each one.
1. Health and safety legislation and the CDM Regulations
You must understand relevant UK health and safety legislation, in particular the Construction (Design and Management) Regulations (CDM). Each company has different minimum requirements, but typically accepted qualifications include Energy & Utility Skills Register (EUSR) Safety, Health and Environmental Awareness (SHEA) Power, Institution of Occupational Safety and Health (IOSH) and National Examination Board in Occupational Safety and Health (NEBOSH).
- EUSR Safety, Health and Environmental Awareness (SHEA) Power
- IOSH or NEBOSH: call us on 01926 674340 and we can advise on the right course.
We also recommend:
2. Impressed Voltage
You must understand the causes and consequences of Impressed Voltage. The Lead Contractor Design Approval Engineer (LCDAE) and the Principal Designer Representative (PD Rep) must make sure Impressed Voltage hazards are captured and eliminated or mitigated in the design. We recommend:
3. Environmental and waste management
You must understand the general requirements of UK environmental and waste management legislation. We recommend:
4. Sustainability
You must understand the general principles of sustainability. SR212 Sustainable Construction is covered on our Contractor Design Approval Engineer (CDAE) / Lead Contractor Design Approval Engineer (LCDAE) / Principal Designer Representative (PD Rep) course.
5. Your organisation’s Design Management Procedures
You must have a working knowledge of the contractor organisation’s own Design Management Procedures.
6. NGET Generic Scope of Work and Supplier Requirements
You must have a working knowledge of National Grid Electricity Transmission (NGET)’s Generic Scope of Work and SR106, SR107, SR135, SR141, SR163, SR183, SR188, SR234 and SR241. We recommend:
7. NGET Technical Specifications
You must have appropriate knowledge of the Technical Specifications relevant to your discipline. We are currently looking at what training we can develop to support this requirement.
Additional requirements for CDAEs
- the skills and experience to lead the contractor’s project design team, including acting as spokesperson and providing inter-technology coordination
- the skills to produce, maintain and deliver the project Design Programme
- enough general knowledge of the technical disciplines in the project to coordinate the design and its interfaces
- a proven track record of delivering coordinated multi-disciplinary designs to time and quality on relevant projects
A statement of experience may be used in place of, or alongside, training for these requirements.
What employers and NGET look for beyond the form
The SR188.12 form sets the minimum. In practice, contractors and National Grid Electricity Transmission (NGET)’s Design Assurance Engineers typically expect a Contractor Design Approval Engineer (CDAE) to have:
- A design background in the discipline, for example as a design engineer or senior design engineer in Substation High Voltage, Protection and Control, Civil, Overhead Line or High Voltage Cable design
- Typically a minimum of 2 years’ experience on NGET projects, usually alongside wider transmission and distribution design experience
- A proven track record of coordinated, multi-disciplinary designs delivered to time and quality
- Working knowledge of the NGET Technical Specifications for their discipline, and of Type Registration
- Hands-on experience of the SR188 process, such as preparing Design Packages and Design Compliance Audit Assurance Reports (DCAARs), attending Design Review Meetings and managing design changes
- A relevant degree and membership of a professional institution, such as the Institution of Engineering and Technology (IET) or the Institution of Civil Engineers (ICE), with chartered status preferred by some employers
For the Lead Contractor Design Approval Engineer (LCDAE) role, employers typically look for previous experience as a CDAE, plus experience leading a multi-disciplinary design team and managing a Design Programme.
Always talk to your Design Assurance Engineer
Before you are nominated, always talk to National Grid Electricity Transmission (NGET)’s Design Assurance Engineer (DAE) for your discipline. The DAE carries out the competence check on every Contractor Design Approval Engineer (CDAE) and Lead Contractor Design Approval Engineer (LCDAE) nomination, so they can tell you what NGET will expect to see in your competency matrix and experience record, whether full or limited CDAE status is more appropriate, and how to strengthen your application. Contractor Design Approval Engineer – Limited [CDAE (Limited)] status must also be agreed with NGET’s Authorising Manager, Engineering Services, before the form is submitted.
Please note: this is for information only. Every contractor has its own competency matrix for the CDAE and LCDAE roles, and NGET reviews each nomination individually. Always liaise with the organisation that will nominate you, and with the DAE, to confirm the requirements before booking training or applying.
Documents and competence check for SR188.12
- Completed SR188.12 form, including the application type: new full, new limited, moving from another contractor, or consultant appointed by the contractor
- Curriculum vitae (CV)
- A competency matrix for the role, with a scoring mechanism; the candidate’s score must meet or exceed the minimum for every criterion
- A relevant experience record covering National Grid (NG) projects, other Electricity Supply Industry work and other relevant design experience
The form must be signed by a director or senior manager of the contractor organisation directly contracted to National Grid. If the Contractor Design Approval Engineer (CDAE) or Lead Contractor Design Approval Engineer (LCDAE) is sub-contracted, the declaration must still come from the contractor organisation; a declaration from the sub-contractor is not accepted.
National Grid Electricity Transmission (NGET)’s Design Assurance Engineer for the discipline then carries out a competence check. If accepted, the individual is added to NGET’s master record of CDAEs and LCDAEs. This entry is not transferable, so a CDAE who moves to another contractor needs a new application.
How to become a CDAE or LCDAE: a typical route
Becoming a CDAE
- Start as a designer in your discipline, building experience of substation, Protection and Control, civil, overhead line or cable design.
- Gain National Grid Electricity Transmission (NGET) project experience, typically at least 2 years, so you understand NGET’s specifications, Supplier Requirements and design assurance process.
- Learn the SR188 process in practice, working alongside an existing Contractor Design Approval Engineer (CDAE) on Design Packages, Design Compliance Audit Assurance Reports (DCAARs), Design Review Meetings and design changes.
- Complete the SR188.12 prerequisite training: a health and safety qualification such as Energy & Utility Skills Register (EUSR) Safety, Health and Environmental Awareness (SHEA) Power, Institution of Occupational Safety and Health (IOSH) or National Examination Board in Occupational Safety and Health (NEBOSH) (as your organisation requires), Construction (Design and Management) (CDM), Impressed Voltage, environmental and waste management, and sustainability.
- Talk to the Design Assurance Engineer for your discipline about what NGET will expect, and whether Contractor Design Approval Engineer – Limited [CDAE (Limited)] is the right first step.
- Be assessed against your organisation’s competency matrix and nominated on the SR188.12 form.
Becoming an LCDAE
- Build experience as a Contractor Design Approval Engineer (CDAE) first. You typically cannot become a Lead Contractor Design Approval Engineer (LCDAE) without having held the CDAE role.
- Lead multi-disciplinary design teams, coordinating interfaces between disciplines and with work by others.
- Own a Design Programme and the Design Intent Document process.
- Talk to the Design Assurance Engineer before your organisation nominates you as LCDAE.
Why are CDAEs in demand?
- Every discipline needs one. A Contractor Design Approval Engineer (CDAE) is required for each Core Design Discipline on every project, and a Lead Contractor Design Approval Engineer (LCDAE) for the project overall.
- Approval doesn’t travel. Entry on National Grid Electricity Transmission (NGET)’s register is not transferable between contractors, so each contractor needs its own approved CDAEs.
- The accountability is high. Signing a Design Compliance Audit Assurance Report (DCAAR) means confirming you have checked 100% of the design.
- Investment in the transmission network means more projects and more design packages to approve.
Please note
This article is for information only. It is based on NG/ET/SR188, NG/ET/SR163 and the SR188.12 appointment form, together with typical industry expectations. Each contractor has its own competency matrix for the Contractor Design Approval Engineer (CDAE) and Lead Contractor Design Approval Engineer (LCDAE) roles and may set different or additional requirements. Always check with your own organisation, liaise with National Grid Electricity Transmission (NGET)’s Design Assurance Engineer for your discipline, and refer to the current issue of each NGET document.
How Pragmatic Consulting can help
We help contractors and individuals prepare for SR188.12 appointment. Our interactive two-day National Grid CDAE / LCDAE / PD Rep Supplier Requirements Awareness Training covers SR188 in depth, from the Design Intent Document to Design Compliance Audit Assurance Reports (DCAARs), design change control and Hazard Review. It includes scenarios, questions and a homework presentation on day 2, and can be delivered at Stoneleigh Park or on-site for groups.
We also run the other prerequisite courses: EUSR SHEA Power, Impressed Voltage for Designers, CDM 2015 Awareness and CITB SEATS. Call 01926 674340 to talk to the team.
Working with the site team? Read our guide How to Become a Site Manager on a National Grid Substation, which explains the SR163.11 Principal Contractor Representative (PC Rep) role your designs will be built under.
FAQs
What is a CDAE?
A Contractor Design Approval Engineer (CDAE) is appointed by the contractor for one Core Design Discipline. They check 100% of the design in their discipline and sign the Design Compliance Audit Assurance Report (DCAAR) for each Design Package before it goes to National Grid Electricity Transmission (NGET).
What is the difference between a CDAE and an LCDAE?
The Lead Contractor Design Approval Engineer (LCDAE) takes overall accountability for the contractor’s design process, leads the design team, owns the Design Programme, signs off the Design Intent Document (DID) and chairs Design Review Meetings. Contractor Design Approval Engineers (CDAEs) are responsible for the design in their own discipline. One person can hold both roles.
What is CDAE (Limited)?
A Contractor Design Approval Engineer (CDAE) authorisation with reduced competency requirements, for simpler or single-technology projects and specialist areas such as tunnels or High Voltage Direct Current (HVDC). It covers one discipline and is not transferable between projects.
How much NGET experience do I need to be a CDAE?
SR188.12 does not set a number of years, but typically employers and National Grid Electricity Transmission (NGET) expect a minimum of 2 years’ experience on NGET projects, with a design background in the relevant discipline. Requirements vary, so always check with the nominating organisation and the Design Assurance Engineer.
Can I become an LCDAE without being a CDAE first?
Typically not. The Lead Contractor Design Approval Engineer (LCDAE) takes overall accountability for the design process, so employers and National Grid Electricity Transmission (NGET) usually expect previous experience as a Contractor Design Approval Engineer (CDAE).
Who should I talk to before applying?
Your own organisation, which will nominate you and assess you against its competency matrix, and National Grid Electricity Transmission (NGET)’s Design Assurance Engineer for your discipline, who carries out the competence check and can advise on what NGET will expect to see.
If I move to another contractor, am I still a CDAE?
No. Entry on National Grid Electricity Transmission (NGET)’s master record is not transferable between contractors. Your new employer must submit a new SR188.12 form.
Who signs the SR188.12 form?
A director or senior manager of the contractor organisation directly contracted to National Grid. A declaration from a sub-contractor organisation is not accepted.
What is the difference between Substation HV and P&C design?
Substation High Voltage (HV) is the primary design: the High Voltage plant, layout, clearances, busbars and earthing. Protection and Control (P&C) is the secondary design: protection, control, metering and auxiliary systems. Each is a separate Core Design Discipline with its own Contractor Design Approval Engineer (CDAE).
How long does it take to become a CDAE?
It depends on your design experience and track record. Typically, you will need a design background in your discipline and at least 2 years on National Grid Electricity Transmission (NGET) projects to become a Contractor Design Approval Engineer (CDAE), and experience as a CDAE before becoming a Lead Contractor Design Approval Engineer (LCDAE). Contact us and we can review your current certificates against the SR188.12 requirements.
