New back door

[TheE1ementsSong]

I need to replace my old back door as it's become very warped and draughty, makes the kitchen horribly cold in the winter.

I don't know whether it's worth it to get a composite rather than UPVC, whether I can have a cat flap installed, etc. I've never bought a door before! Any advice much appreciated.

There is a big difference in price between upvc and composite but the latter is better, more secure too. You should be able to have a cat flap at the manufacturing stage which will likely be a better job.
I have a composite stable door on my kitchen and absolutely love it.

That is very helpful @caramac04 - I have to admit, just from looking at images online that I much prefer the look of the composite doors. I quite fancy a stable door now that you mention it!

Hallmark do great composite doors and can put you in touch with a local fitter too. www.hallmarkpanels.co.uk
You can have a cat flap fitted but it needs to be on one of the flush designs like a Cottage Escala 1 as opposed to a panelled door like a Mulsanne 1 as otherwise it doesn't seal properly.