Tony wrote:
Why is it always the simple things that take so much effort to get
right?!

So I'm revamping the kitchen and one of the jobs involves replacing a
fitted cooker hood with a stainless-steel chimney hood. Fine, I think.
I'll just take the existing hood out (job done) and screw in the new
hood.

But OH NO. The new hood is too "tall" for the kitchen (and we don't
have a particularly low ceiling). The required gap between the hob and
the hood is 70cm (manufacturers specification) which leaves the
chimney part of the hood some 15cm into the ceiling space! And this
is with the chimney set to it's minimum dimensions...

Either I cut a hole in the ceiling (no way - not just for a cooker
hood!) or I trim the hood itself.

or place the hood slightly below the manufacturers recommendation.