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  • Writer's pictureDavid Taylor

FENSA, CERTASS & Building Control

There is often a degree on confusion when people discuss FENSA, CERTASS and Building Control, so I thought it would be useful to discuss the similarities, differences and what you need to know if you are planning to have new windows and doors installed.

Most reputable window, door and glazed roof installers in the UK are registered with either FENSA or CERTASS. These are Competent Person Schemes that work within the fenestration industry and were set up in response to Government legislation. Electricians have NICEIC, gas heating engineers have the Gas Safe Register and in the fenestration industry we have FENSA and CERTASS.


In a nutshell, registered members of Competent Person Schemes are able to 'self-certify' their own installations, instead of the homeowner having to get building regulations approval for whatever installation has been carried out. In other words, the homeowner doesn't need to get a local council or private approved building inspector in to approve the work and provide a certificate. Additionally, the homeowner benefits financially by not having to pay a fee for this additional service.

So at the end of a project, a FENSA or CERTASS installer will provide the homeowner with a certificate which basically show that the windows, doors etc. have been installed to current building regulations. These certificate are particularly useful when you go to sell your house in the future, as they are evidence that the work was done 'properly'.


As you would suspect, both FENSA and CERTASS have a formal assessment process for installers wishing to be registered, the successful completion of which results in the installer being issued a registration number and the ability to use the relevant schemes logos etc. in their marketing material. Their membership also provides the installer with additional services including technical support and advice.

So, other than the fact that FENSA have considerably more members, 9,000 to CERTASS' 2,000 (partly due to the fact that FENSA have been around longer) there is very little difference between them. At least as far as the homeowner is concerned.

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Building Control on the other hand have a much broader scope of work. Traditionally, Building Control where only to be found within a department of all local councils. However, more recently this is now a service that can be provided by private building inspectors. Whichever you choose to provide the service on your project their role is the same, that being to inspect and certificate and building works that are covered by building regulations. That includes all structural works, for example an extension or a new build house, including the fenestration. However, where as FENSA and CERTASS can only 'sign-off' the fenestration installation, building control can 'sign-off' all of a project. From the foundations and drainage, through to the insulation and fire protection. And yes, the windows, doors and roof glazing.

So far so good. But here comes the twist.....

FENSA and CERTASS only cover replacement fenestration. They do not cover windows, doors and roof glazing that are being installed in a new extension or new build house.

So the question we need to ask ourselves is, do I need to employ the services of a FENSA or CERTASS registered installer if my fenestration is going to be installed into my new extension or house? Well the answer is no you don't, because they will be signed off by the building inspector when they sign off the whole project. In fact many builders I know install the fenestration on projects that they are working on and are not FENSA or CERTASS registered because of this fact. Although it probably goes without saying that they need to be experienced in installing fenestration as it will only get rejected by the Building Inspector if it is not done properly.

However, despite the fact that the fenestration installer on a new extension or house does not have to be FENSA or CERTASS registered, many homeowners and builders still prefer the job to be done by a registered installer, because that is their area of expertise.

Finally, when it come to replacement windows, the homeowner has a choice. Employ the services of a FENSA or CERTASS registered installer (who can self certificate the project), or employ the services of an unregistered installer and then have the project signed off by a building inspector. As I mentioned above, there will be a fee levied for this service which is approximately £100 for up to five windows.

I hope this help, but if you have any questions please do not hesitate to comment below.

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