If you’re thinking about getting solar panels that sit inside your roof (in-roof or integrated solar), there are some important safety changes you need to know about.
A recent rule change means that many in-roof solar systems no longer meet fire safety standards, and some installers may be selling systems that aren’t properly tested.
This guide explains:
✅ What’s changed
✅ How to check if your solar system is safe
✅ Why this doesn’t affect solar panels that sit on top of your roof
What Has Changed?
In September 2023, the rules around fire safety testing for in-roof solar panels changed. Before, testing companies could use their expert opinion to say that similar systems were safe without actually testing them together. That is no longer allowed.
Because of this change:
- New in-roof solar systems can’t currently get fire safety certificates unless they have been fully tested.
- Many older in-roof systems that were previously approved no longer meet the new standard.
- Some installers may still be offering these systems without knowing they are non-compliant.
What’s the Difference Between MCS 005 and MCS 012?
The Microgeneration Certification Scheme (MCS) is the body that checks solar panels and mounting kits meet UK standards. It has two different sets of rules:
✔️ MCS 005 – This applies to solar panels. It checks they work properly and are safe.
✔️ MCS 012 – This applies to in-roof mounting kits (the parts that hold the panels inside your roof). It checks fire safety and weather resistance.
Why does this only affect in-roof systems?
🟠 On-roof solar panels (the ones that sit on top of roof tiles) don’t need MCS 012 certification because they are separated from the roof by air, reducing the fire risk.
🟠 In-roof solar panels replace part of your roof, meaning they must be tested for fire safety with the mounting kit they are installed with. You can’t just mix and match panels and mounting kits unless they’ve been tested together.
Why Does This Matter to You?
For an in-roof solar system to be MCS 012 compliant, the specific solar panel and mounting kit must be tested together. Just because a panel is MCS 005 certified and a mounting kit is MCS 012 certified does NOT mean they are safe together.
⚠️ If your in-roof solar system doesn’t have the right certification, you could face:
✔️ Legal issues – It may not meet UK fire safety rules.
✔️ Home insurance problems – Some insurers may refuse to pay out if an uncertified system is involved in a fire.
✔️ Problems selling your home – If the system isn’t certified, it may fail surveys or scare off buyers.
✔️ Fire risks – Uncertified systems haven’t been tested properly inside a roof structure.
Which In-Roof Solar Panels Are Still MCS-Compliant?
Since many previously tested solar panels are no longer available, the options for fully certified in-roof solar systems are now very limited.
At the time of writing, Viridian Solar’s Clearline Fusion is one of the few widely available in-roof solar systems that still meets MCS 012 certification requirements this is largely because their system is manufactured as a full solution – the mountings and panel can only be tested together and so although the issue has prevented them from increasing their output from 405Wp the historic testing still stands the test of time and they still have tested panels in circulation (other tested panels have since been sold and higher output panels released to market).
Viridian’s Clearline Fusion system is fully tested and approved as a combination, making it:
✔️ Fire safe
✔️ Fully MCS 012 certified
✔️ Compliant with UK Building Regulations
✔️ A future-proof option for homeowners
How to Check If Your System Is Safe
To protect yourself, follow these simple steps before agreeing to an installation:
✔️ Ask your installer for proof of MCS 012 certification for the exact combination of solar panel and mounting kit they are using.
✔️ Check the MCS Product Directory (MCS Product Directory) to confirm the system is listed as compliant.
✔️ Be cautious of misleading claims – Some installers may wrongly assume any MCS 005 panel can be used with any MCS 012 mounting kit. This is not true unless they have been tested together.
What Happens If You Ignore This?
Some installers may say fire testing isn’t important or tell you it’s just a formality. But ignoring these rules could cost you later:
⚠️ You could have to replace your solar system at your own cost if it’s found to be non-compliant.
⚠️ Your home insurance may refuse to pay out if a fire involves an uncertified system.
⚠️ If you sell your home, a non-compliant solar system may cause legal and financial issues.
MCS 012 certification is not just red tape—it’s a vital safety measure to prevent untested, potentially dangerous systems from being installed in people’s homes.
Final Thoughts
If you want an in-roof solar system, do your research and ask for proof of MCS 012 certification for the exact system being installed. Don’t assume any panel and mounting kit will work together – only tested and approved combinations are safe.
By choosing a fully tested and certified in-roof system, you’ll ensure your solar investment is safe, compliant, and future-proof.
