Just been thinking, over the years I have read quite a few books in which a character has made a coffin. (Moberg: The Emigrants being the latest). Another book had a chap who IIRC cut seven planks and used them for his bed until needed. Indeed, we recently found that my partner's great grandfather was the local carpenter and undertaker in Great Tey.
Other than the most obvious requirement of being the right size, are there any rules (Part Z?) on their construction?
I imagine that, if destined for the crem., there could be restrictions on use of metal, wood treatments, etc.
So, any advice if I wanted to make my own?