What constitutes a "bedroom"?

Most Realtors think that a bedroom must have three things to be officially called a bedroom:

1. A door
2. A window
3. A closet

Because that's what's taught to us from the day we get our licenses.

That is not always the case, however.

For example, in Fairfax County, a room is constituted of any space that:

1. Has "emergency egress"
2. Has a smoke detector
3. Is at least 70 sq. ft. in size

Here are the guidelines from Fairfax County.