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
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Flexible Learning
Classroom, online live & guided learning
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Assignments & portfolio guidance included
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500+ Learners Trained in Just Last Year
Ongoing Portfolio Support
City & Guilds Approved Centre
Industry-recognised UK qualification
Experienced Tutors
Taught by working assessors
Online Learning Materials
Comprehensive study resources & portal access
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

Real reviews from our Google profile

Frequently Asked Questions

What is the difference between the 3-Day Online DEA course and the 2-Day Weekend DEA course?+

Both courses cover exactly the same Level 3 Domestic Energy Assessor syllabus and lead to the same recognised qualification. The training materials, assignments, portfolio requirements and assessment criteria are identical.

The only difference is how the training is scheduled.

The comparison below shows the difference between the two delivery options.


3-Day Course (Weekdays)2-Day Course (Weekend)
DaysMonday – WednesdaySaturday – Sunday
Start Time9:30 am8:30 am
Finish Time3:30 pm5:30 pm
Daily Training Hours6 Hours9 Hours
Total Duration3 Days2 Days

As you can see, the weekend course has longer training days, allowing us to cover the same syllabus in just two days. No topics are omitted or shortened, and every learner receives the same training materials, tutor support and guidance.

Whichever option you choose, you'll complete the same assignments and portfolio before achieving the same recognised qualification.

If weekdays are difficult because of work or other commitments, the 2-day weekend course offers a convenient way to complete your training without taking time off.

Are the Retrofit Assessor courses also City & Guilds approved?+
Yes — both Level 2 and Level 4 Retrofit Assessor qualifications are City & Guilds approved, giving you a nationally recognised qualification that meets industry standards.

One of the key advantages of training with Ozone Group Training is the flexibility you'll have once you've qualified.

Unlike some training providers that are linked to a single accreditation scheme, our courses are independent of any one scheme. This means that once you've successfully completed your qualification, you're free to choose the accreditation scheme that best suits your needs, whether that's based on membership fees, support, software, insurance options or additional services.

This gives you the freedom to compare providers and select the scheme that's right for your business or career, rather than being restricted to a single option.

If you're unsure which accreditation scheme to join after qualifying, we'll be happy to explain the available options and help you choose the one that best matches your circumstances.

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.

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.