Replacing a “tin” roof, any pointers?

[SamT]

Pete/phil.. I work i. the industry and we can have this chat offline.  CBA typing long stuff on my phone. I'll mail you tomorrow but got a funeral to go to so quite a busy day for me already.

[PeteHall]

Worth bearing in mind that Castleton is in a conservation area, so you may need planning permission to re-clad the roof.
https://www.peakdistrict.gov.uk/looking-after/living-and-working/your-community/conservation-areas

It would certainly be worth investigating this before buying any materials as planning officers can be hard work, particularly if you get off to a bad start...

The best approach is probably to speak to the conservation officer who covers the area and get their view on what sort of thing might be acceptable. Technically, they will want to charge you for a pre-app consultation for this, but you might find that they are just pleased you want to talk to them and have an off-record discussion for free. Once you know the sort of thing they will accept, choose your preferred product and provide a sample with the planning app and hopefully they will accept it.

I doubt that they will be interested in the construction details (unless it's listed), it will be the appearance that they care about, but you might still be able to blag anything as an improvement 

[pwhole]

Pete - don't worry, we've done all that - but thanks

[Chocolate fireguard]

I think SamT is right.
Unless you are going to do something like putting insulation on the walls (I imagine you are not) and replacing that sliding door (with a wall and a decent door) then you won’t be wanting to heat the space, and without that there is little point in insulating the roof.
I would have thought a reflective (white?) outer layer with 40 or 50mm insulation, as suggested by Down and beyond, would be about right.

Wrong wrong wrong wrong wrong.

Now come on, if you think I made a mistake tell me straight.
I might be sad for a while, but I'll get over it!