clearSkies Certification Explained: Above and Beyond Ecodesign

clearSkies Certification Explained: Above and Beyond Ecodesign

The UK government is taking the environmental impact of the country's heating solutions more seriously than ever. If you heat your home with firewood or wood briquettes, then you've undoubtedly noticed the introduction of several new standards and regulations in the last couple of years alone.

In 2021, Defra introduced the Ready to Burn standard, which made it illegal for anyone to sell firewood and briquettes that contain more than 20% moisture. On January 1, the EU-developed Ecodesign woodstove regulation came into force in the UK. This regulation limits the amount of particulate matter that wood-burning appliances can release during normal operation.

And while most wood fuel users are already familiar with Ecodesign, there's yet another wood burner emissions standard that one might encounter when purchasing a wood stove. That standard is clearSkies.

So what is the clearSkies wood-appliance standard? Why are there several levels to it? What does each clearSkies rating mean? And are clearSkies stoves necessarily better than Ecodesign-certified stoves?

Take 5 minutes to read this article and you will know more about the clearSkies standard than 98% of people in the UK.

What Is clearSkies?

ClearSkies is an industry-run, voluntary self-regulation scheme that grades solid fuel stoves on their emissions and energy performance. Its main goal is to make it easier for consumers to compare the environmental impact of wood stoves from different manufacturers when making a purchasing decision.

Who Runs the clearSkies Certification Scheme?

The certification scheme is run by clearSkies Mark Ltd, an independent not-for-profit company established by stove manufacturers as part of the industry's self-regulation efforts.

Is clearSkies Certification Mandatory?

Unlike Ecodesign, clearSkies certification is not mandatory in the UK. This being said, the certification scheme is endorsed by Defra, the Scottish Government, the Welsh Government, as well as the Federation of British Chimney Sweeps.


                               A burning, clearSkies compliant wood stove.

Are clearSkies Stoves More Efficient Than Ecodesign Stoves?

All clearSkies Stoves are Ecodesign-compliant. Stoves certified as clearSkies Level 4 are at least 15% more efficient than what is required by Ecodesign. And Level 5 stoves are at least 15% more efficient than Level 4 appliances.

What Does Each clearSkies Rating Mean?

There are four clearSkies efficiency levels and their meaning in plain English:

  • clearSkies Level 2: The lowest efficiency level available. The stove complies with the Ecodesign standard.
  • clearSkies Level 3: The stove is both Ecodesign compliant and Defra-exempt.
  • clearSkies Level 4: The stove is at least 15% more efficient than is required by the Ecodesign standard. All Level 4 stoves are Defra-exempt.
  • clearSkies Level 5: The highest efficiency level. The appliance is at least 15% more efficient than what is required for it to be certified as clearSkies Level 4. All Level 5 stoves are Defra-exempt.
  • Are All clearSkies Appliances Ecodesign-Compliant?

    Yes, all clearSkies-certified appliances are also Ecodesign-compliant. The lowest efficiency rating of clearSkies, Level 2, is equivalent to basic Ecodesign certification.

    Are All clearSkies Approved Stoves Defra-Exempt?

    No, only appliances with a clearSkies rating of 3 and above are Defra-exempt. 


    A burning wood stove located in the outdoors.

    What Particulate Matter Does clearSkies Measure?

    The clearSkies standard measures the maximum levels of emissions of the following types of emissions:

    • Particulate Matter (PM)
    • Carbon Monoxide (CO)
    • Organic Gaseous Compounds (OGC)
    • Nitrogen Oxide (NOx)

    Does clearSkies Regulate Carbon Dioxide Production?

    No, the clearSkies standard does not regulate how much carbon dioxide is produced during wood combustion.

    What Is the Difference Between Ecodesign and clearSkies?

    Ecodesign is a mandatory, government-run certification scheme for wood-burning appliances. clearSkies is a stricter, voluntary standard that is run by the stove industry as a self-regulation initiative.

    Is It Illegal To Buy a Stove Without clearSkies Certification?

    No, unlike Ecodesign, clearSkies certification is 100% voluntary.

    What Is the Best clearSkies Rating?

    As of March 2022, Level 5 is the highest efficiency rating a wood-burning stove can achieve.