What is FENSA, and is it a legal requirement?

If you are looking to install new double glazing in your property, understanding the role of FENSA is crucial. The acronym stands for Fenestration Self-Assessment Scheme, and it was set up with the approval of government bodies by the Glass and Glazing Federation (GGF).

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The organisation regulates double glazing companies and ensures compliance with building regulations. You can either acquire permission and certification for thermal performance from your local authority or employ an installer that is FENSA accredited.


Moreover, a FENSA registered installer will have employees working under the Competent Person Scheme certifying your installation. This means you do not have to deal with the certification yourself and the responsibility is in the hands of the company you employ. That responsibility remains with them; details can be found at the GGF site.

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Whether you are looking for a supplier of double glazing in Gloucester, Glossop or Glasgow, you will find suppliers at sites such as firmfix.

As of 1st April 2002, any new or replacement glazing is subject to Building Regulations and requires approval.

If the installer is FENSA registered, he may issue a FENSA certificate in lieu of a Building Regulations completion certificate. He must also notify the Building Control Department at the local authority of the work.

If the installer is not FENSA registered, the work must be inspected by building control and a completion certificate must be obtained.

Legal changes

If you’re selling a property and you’ve replaced or installed windows since April 2002, locate your certificate; the buyer’s conveyancing lawyer will ask for it.

FENSA was established as a result of these legal changes, which recognised that double glazing installation had to be standardised to lower the carbon footprint of housing by reducing heat exchange in the property and lowering energy use and costs.

By regulating the thermal performance of the glazing in the building, FENSA and GGF are helping to reduce energy consumption and meet government targets. In the wake of recent fire incidents such as Grenfell, these bodies also aim to improve ventilation and fire safety issues.

Although others offer Competent Person Schemes, FENSA is by far the most popular regulator.

FENSA regulated companies are available on their website. Keep in mind that they must provide insurance for their work