Standard caravan height - is there such a thing?

[oop north]

Getting a quote from a builder to do some work on an outbuilding that I use as garage (35 feet by 24 feet - former dairy / milking parlour). At the moment it has a doorway in one end that is fairly standard height so not tall enough to get a caravan in but wondering about asking extra cost of making it taller to be able to do so. there would be space to hold caravan and a couple of cars and still have lots of storage

I don't want to get it sorted for the current caravan and then discover a later one won't fit in cos it's a bit taller. Is there a standard caravan height?

[oop north]

Ta (9 to 10 feet is quite a spread!) - but I will also have look on t'web and maybe ask a dealer or two

[oop north]

Think I'd struggle to get that anywhere near the garage door, let alone through it!

Don't want 12' that's a bit OTT- better get my tape measure out!