Hi anna_cannon, having a plan drawn is a good start, you might want to put the dimension on the plan as well just to help others know exactly where everything is. This is what I think works given the information I have. Not sure if you how much renovation you are looking at and whether you need both doors to the back but I kept them just in case. Basically I have grouped similar functions together such as (freezer, pantry) (linen, washer/dryer, sink), and (bench, coat hanging close to the doors in the back) ... all the plumbing stays the same to keep cost down. Hope this gives you an idea on what's possible in your multi-functional space.

I think the first layout is fine. You might want to consider moving the door for the storage room of the master bedroom so that it opens into the hall. That way the kids can use it for overflow storage. Also, that hallway is big enough that I think it could hold a large armour, providing more closet space. (There's no need to sleep in the same room as your clothes, so long as they're not too far off.) Also, don't forget that while the drawing shows kids in double beds, this need not be the case, so there will be more room for furniture (dressers or whatever) in their rooms. Finally, that step to bedroom 4 will not be odd at all. I've seen it in other homes. It looks clumsy in the drawing but it isn't. What you'll see when you come up the stairs is a bedroom door on a slight diagonal. It's only an odd jagged step if you walk like a robot, in straight lines along the wall, which is what your eye is doing on the drawing but you won't do in real life.

I have a cabinet already should fit there, so did think about that already...maybe I am just having a hard time picturing it. We are designing a 'contemporary' house, so I would say it is fairly modern with touches of older/more vintage pieces. I will take a picture of my cabinet tonight to see what you guys think. But I guess most photos/when I think of buffet cabinet I picture more traditional pieces. If anyone has a more modern take would be great!

A version of one of these might work for your dilemma. Surely one of them can be tweaked to work for your window.