compound adjectives with numbers

[yiota]

Hello,
I'd like to ask if there are any rules regulating the choice between
A + Numeral + Noun (a sixteen-week semester, a two-bedroom flat)
and
A+Numeral+Noun+ed (a one-layered disk, a three-headed monster)
constructions used as noun modifiers.
Is it the nature of the defined noun, the relations between the noun and the attribute or something else that tells us what construction to choose? And what would be the right way to say: a three-storey house or a three-storeyed house?

[svartnik]

Originally Posted by yiota

Hello,
I'd like to ask if there are any rules regulating the choice between
A + Numeral + Noun (a sixteen-week semester, a two-bedroom flat)
and
A+Numeral+Noun+ed (a one-layered disk, a three-headed monster)
constructions used as noun modifiers.
Is it the nature of the defined noun, the relations between the noun and the attribute or something else that tells us what construction to choose? And what would be the right way to say: a three-storey house or a three-storeyed house?

one-layer/layered disc
a sixteen week (not weeked) semester
three-headed (not head) monster

It seems a bit all around a lot.