0203 488 2554 training@ozonegroup.co.uk

Build Your Career inEnergy Assessment & Building Compliance

City & Guilds approved training in Domestic EPCs, Retrofit, SAP, Non-Domestic Energy Assessment and more. Flexible learning. Expert tutors. Real-world support.

Expert Tutors
Learn from industry professionals
Flexible Learning
Classroom, online live & guided learning
Practical Support
Assignments & portfolio guidance included
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Ongoing Portfolio Support
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Industry-recognised UK qualification
Experienced Tutors
Taught by working assessors
Online Learning Materials
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Portfolio Support
Hands-on assignment guidance
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Featured Courses

Our most popular Energy Assessor qualifications

Why Ozone

Why Choose Ozone Training

We're working Energy Assessors who train new assessors — not a generic training company.

  • Run by practising DEAs since 2011
  • City & Guilds approved courses
  • Real-world tips, not just exam-pass content
  • Spread cost in interest-free instalments
  • 100% pass guarantee with free re-sits

What Our Learners Say

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Frequently Asked Questions

Can I assess every commercial building after qualifying?+
Not necessarily. Your permitted scope depends on your qualification and accreditation level. More complex buildings may require higher-level competence or different modelling methods.
What if I fail an assignment?+

There's no need to worry. We don't expect every assignment to be perfect the first time.

If your assessor feels that an assignment needs further work, they'll provide clear, constructive feedback explaining what needs to be improved. You'll then have the opportunity to make the required changes and resubmit your work.

There is no limit on the number of resubmissions, so you can continue improving your assignments until they meet the required standard. Our goal is to help you understand the subject and successfully complete your qualification, not to catch you out.

Throughout the process, you'll have access to tutor support whenever you need it. If you're unsure about any feedback or need additional guidance, your tutor will be happy to explain what's required and help you move forward with confidence.

We believe learning should be supportive rather than stressful, which is why we work with you every step of the way until you've successfully completed your portfolio and achieved your qualification.

How long does it take to qualify after completing the Domestic Energy Assessor (DEA) course?+

The time it takes to achieve your Level 3 Domestic Energy Assessor qualification depends on the training option you choose and how quickly you complete your portfolio.

Classroom Courses:
If you attend one of our classroom-based Domestic Energy Assessor courses and have completed all the required assignments before or during the course, your portfolio can often be reviewed and signed off during the classroom session itself. This is the fastest route to qualification for learners who arrive fully prepared.

Online Courses:
For our online training, you complete your portfolio after your live online sessions. Most learners who dedicate 2 to 3 hours per day to their assignments can realistically complete everything within around one week. Once your portfolio has been submitted, your assessor will review your work and provide feedback where required. If any amendments are needed, you'll receive clear guidance and can resubmit your work.

There is no fixed deadline to complete your portfolio within your course access period, so you can work at a pace that suits your schedule. However, learners who stay engaged and complete a little each day typically qualify much sooner.

Our aim is not simply to help you pass the course, but to ensure you leave with the knowledge, practical skills and confidence to carry out domestic Energy Performance Certificates (EPCs) professionally from day one.

Ready to start your DEA career?

Speak to our team or book your course today. We'll guide you from enrolment to your first paid EPC.