What makes a door external grade?

10 Jan 2007
Reaction score
United Kingdom
I have just had a conservatory built, and need to put an external door between it and the house to be exempt from Building Regulations.

I would like the door to match the internal doors as far as possible, and someone has suggested using an FD30 fire door fitted with safety glass.

These doors actually show as being for internal use, but the fitter's view is that the 44mm thickness, combined with the safety glass is enough for them to qualify as external grade.

Is this correct?
Sponsored Links
Thanks for the replies. It appears that I actually have another door problem. :cry:

The front door should be exempt from the emissions legislation as it is going to be less than 50% glazed (is this correct?). I am hoping the BCO will not be interested in this one.

However, I have recently had a set of fully glazed French doors fitted between the conservatory and original house as well.

These are 'external' per Howdens website and are fitted with safety glass, but are only single glazed, so will presumably never meet the required U value of 2.2 :eek: I am not sure how Howdens can justify selling them as external in this case.

This would appear to be an expensive mistake, but am I correct in thinking I can keep these doors when I come to sell, at which point I can just get a cheap set of uPVC doors put on by a FENSA installer?

Thanks again for the replies.
Sponsored Links
Freddys twin is right, it's a question of thermal performance. The absolute minimum is a U of 2.2 and BCO will require you to demonstrate that the door is at least that or better.

The Howdens external thing is irrelevant because not all external doors are fitted into a heat loss situation. e.g. an unheated conservatory.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local