FENSA and Certass, two of the double glazing industry’s biggest self-certification bodies. But what exactly is the difference between the two?

Lets start off with what we know so far. FENSA currently has a membership of 8713 and Certass can lay claim to 1850 members. Certass is up on previous numbers and FENSA is slightly down. Together they both represent over two-thirds of the double glazing industry, which on the face of it makes for a powerful statement. One of the easiest ways to try and figure out the differences in how they describe themselves:


FENSA stands for the Fenestration Self-Assessment Scheme. Following Government encouragement, FENSA has been set up by the Glass and Glazing Federation (GGF) and other industry bodies in response to Building Regulations for double glazing companies in England and Wales.

Certass Says:

Certass Limited is a UKAS approved certification body for the operation of a Competent Person Scheme under a Department of Communities and Local Government (DCLG) license and a Green Deal Certification Body under licence from the Department for Energy and Climate Change (DECC).

So both have been set up in response to Government legislation, no real differences there then. But if you are in the market to have new windows and doors installed, which do you choose: a FENSA registered company or a Certass registered company?

You could look at what is available. Certass and FENSA are both UKAS accredited, and both have partnerships with various other bodies. But if you’re a homeowner that is looking into getting into Green Deal work, then the fact the Certass is a Green Deal Approved Certification body might boost your interest. Certass also has TrustMark accreditation, which is a logo that is highly respected and easy to recognise. Both schemes ensure that registered installers offer deposit protection as well as insurance policies on top of standard company guarantees.

Certass does seem to provide more when it comes to installer support. They provide services such as bespoke van signage and mediation support should there be a dispute between the customer and an installer.

If badges aren’t your thing, then numbers might be. FENSA has close to 9000 members. They must be doing something right if they can command such a large proportion of the industry. Certass has less than 2000 members. But it is important to look at age here too. FENSA was established in 2002 in response to new Part L changes, whilst Certass became licensed in 2006. If you are a believer in age and history, FENSA has the upper hand here.

As with most things in life, money plays a big factor. From 2014 FENSA’s annual registration fee goes up to £120. Certass however are a not-for-profit scheme and are widely thought to be cheaper than FENSA in the long run.

The current state of play at the moment is FENSA’s membership is on the decline, while Certass membership is on the way up. This could possibly signify a change in loyalties within the industry.

So to address the question of this post, what’s the difference, well, not that much when it comes to the main points. Both are self-certification schemes, both were set up in response to Government legislation, both are UKAS approved with both being able to boast about half a dozen other logos and accreditations each. One thing I would point out is that despite a lot of hype around FENSA and some possibly biased support out there in the industry, Certass are doing a very good job themselves. If you were to ask me if there were any real differences, I would say to you no, there aren’t and that choosing a Certass registered company is just as likely to do a high-quality job on your property.

On a final note, I would say that both are doing their very best to make sure the industry works to all the laws and regulations that govern this industry. Without them, our sector would be in more difficult waters than we find right now.

You can visit the FENSA website here: http://www.fensa.co.uk/

You can visit the Certass website here: http://www.certass.co.uk/

This post was written for Value Doors UK who posed the question: FENSA vs Certass – What’s The Difference? Value Doors UK is a nationwide External Door company based in Yorkshire, manufacturing and installing high-quality products. You can visit them at their website: www.valuedoors.co.uk, catch them on Twitter: @ValueDoorsUK or call them on 0800 955 0898.