In Australia we call this a "Queenslander"Room. Ours was begun in March and dribbled on for a few months...and was nearly ready for use when Council decided the floor had to be dug up because of shoddy worl by a plumber we had who was a raging alcoholic and left work undone under wads of concrete...HMMM...we paid of course as you do.
This addition has made our house just lovely. It was a bit small in places and the furniture didn't have a real home as we need to have a lot of turning room for the wheelchair inside... I am a bit wierd...I just go out there and look at it and sigh... but am not in the habit of really using it yet..., maybe as the weather warms up and before it gets too hot!
Its just bewdiful.