I'd say that's completely unreasonable and here's why:
I pay you to do a job that provides value to my company. You're not providing that value while you're sleeping. You can have nap time, but I'm not paying you to nap. As a coder and software architect myself, I understand that it takes a fresh mind to deliver your best work so I understand the need for sleep and you should have as much as you need - but I'm paying you to do a job, not sleep. You sleep on your own dime, not mine. If you're not coming to work fresh enough to provide what we agreed to when you accepted the job, then why are you still coming to work?
I pay you to do a job that provides value to my company. You're not providing that value while you're sleeping. You can have nap time, but I'm not paying you to nap. As a coder and software architect myself, I understand that it takes a fresh mind to deliver your best work so I understand the need for sleep and you should have as much as you need - but I'm paying you to do a job, not sleep. You sleep on your own dime, not mine. If you're not coming to work fresh enough to provide what we agreed to when you accepted the job, then why are you still coming to work?