Those are good size windows. You can either use them on the sides of greenhouse or as the roof. Here's a link you or others might find useful. http://pimoov.com/greenhouse-design-plans/greenhouse-effect/

For sure you need an achitect and one that has experience with designing compliant homes there are so many things to be aware of. I am on the board of a Society that has all ADA compliant units and the amount of planning that went into them was amazing. Remember it is more than making the bathroom compliant the front door has to be for starters and so on.

How about moving the Master Bath next to the full bath and enlarging both the MBR and the 12' x 12' bedroom? Right now, it looks a bit like a rabbit's warren. How tall are the ceilings? Perhaps you could do a wall of closed wardrobe storage in the MBR rather than a separate walk-in? Do you need both a living room and a family room? How does the other level look?

Yikes. Drivers have to walk around the car(s) (unless you're in G.B., Aus., or Japan) to get to the only door into the house; they should be able to go right into the kitchen area. And that garage is awfully tight. Steps on the ground floor? Why isn't it all one level? You're losing potential buyers with that unnecessary 3-step jog. Everybody who enters the house has to walk right past the kitchen to get to the living room. Why? The kitchen is a work space and should not be exposed like that. Flip the two rooms. I would love to be there when the movers try to get anything into that front left bedroom entrance. The person who goes into the toilet closet in the master bath is going to have a hard time closing the door once they are in that tiny space. And I agree with an earlier post about the front façade. It's really hideous with the windows jammed as they are and not aligned.