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  • So let’s start with what a FENSA actually is…

    FENSA stands for the ‘Fenestration Self-Assessment scheme’ which has been set up by the Glass and Glazing Federation (GGF) as a means to self-certify compliance under Building Regulations without the need for a separate assessment from Building Control.

    The FENSA register collates a list of accredited double glazing installers across England and Wales so that homeowners can ensure they are choosing a reputable and experienced home improvements company. Registered with the government, the Fensa register assures that the double glazing installer is professional, complies with building regulations and offers an insurance backed warranty, for ultimate peace of mind.

    If your installer is not registered with FENSA any works that include replacing windows, doors and roof lights will require you to get a certificate from Local Authority Building Control instead.

    When does FENSA apply to glass rooflights?

    The FENSA scheme does not extend to rooflights so it is not possible for a rooflight installer to provide a FENSA certificate for a rooflight they have installed. It does however extend to roof windows. The distinction between a rooflight and a roof window is that rooflights are generally installed on an  upstand on flat roofs so out of plane with the roof. A roof window is usually installed on pitched tiled roofs and are in plane with the roof so they sit flush with the tiles. Roof windows have to comply with BS EN 14351-1 and should be UKCA marked accordingly.

    FENSA certification can only apply if you are replacing an existing roof window; installation of a new roof window will require certification from Building Control to ensure that any structural changes and thermal performance meet current regulations.

    FENSA also does not apply to conservatories, porches, commercial premises, new build properties or extensions. In all of these instances you are required to go through the Local Authority Building Control process.


    If the roof window is a new addition to your property, or the building itself forms part of an extension or is a complete new build, then FENSA does not apply and you will require approval from Building Control.

    If you are replacing an existing roof window, you can use a FENSA approved installer or alternatively apply for full Local Authority Building Control approval.

    If you are replacing an existing rooflight, or it is a new addition as part of a new extension, refurbishment or complete new build the FENSA does not apply and you will require approval from Building Control.

    Please note that the homeowner is ultimately responsible for ensuring that their roof window or rooflight installation complies with these standards and regulations.

    For more information give us a call on 01379 771002 or browse our online store.