oystehan Hi!
The way it works is if you have Floor Map Designer, you can create your floor maps, and then clicking on "New" in Home Designer will show a menu where the user can select one of the floor map he created to start with.
Now if you want to propose room templates to your users without them having to design their own floor maps, it is possible but not implemented. That's a good idea, I will add that to the road map.
Thanks!