Teenage boys and high-sleeper beds?

[Dogsaresomucheasier]

Just interested to hear how old they are when they outgrow them, please. Dd is our youngest, and destined to be in the box room for some time, so it would make sense to have a high sleeper for storage. How long can I expect the average teenage boy to last in one?
Thanks

Ds! Mumsnet clearly think I only post about the hourly!

Girls! Bloody autocorrect!

12, as could no longer sit up in bed without touching the ceiling. Personally I think a mid sleeper is better value and lasts longer although not cool after 12, we've taken off the cot sides and ladder so the 14 sort of launches himself on it. He would love a normal bed but there isn't enough space. His bed also has storage above the bed height.

I need help here! We have a box room and my two steps sons have bunk beds 14 and 16! I know they are far too old but the room is so small there is no other solution I guess as it's only 4 nights per month its not awful but has anyone got suggestions?

My DS had one until he was around 10/11 ie when he could no longer sit up without bashing his head on the ceiling! I was so relieved to get rid of it because changing the bedding was an absolute pain!