whens a bedroom not a bedroom

So whens a bedroom not a bedroom...

The question we are asking as turns out the bonus sun room aka den which we love means that the 4th bedroom doesn't have an egress to the outside although it does to the sun room. So how do you make a room then a non bedroom that it then meets the building code. Some sites say its no closet which could be tricky to remove

Bob Villa says its a matter of having no door so to the room and calling it a bonus room. Since we mean it to be an office anyway that would work for us. Lets see if it works for the bank.

And to think all I was thinking about was how do we change the horrible colour of the pathway to the house thats painted a sickly sea blue green....