Although they would make a very soft, comfortable, tasty home I am not so sure they would work the best for building a full size home out of...
Marshmallows; that tasty treat we put in Rice Krispie squares, make fondant from or take along while camping for S'mores. Oh! and occasionally shoot at each other are now a favorite building tool in our home. All you need is a set of toothpicks and some mini marshmallows. I am sure that it would work just as well with full sized marshmallows and skewers but we have not adventured that far as of yet. Making a mental note to give that one a try very soon.
Start with 4 marshmallows and 4 toothpicks to create your square base. I find that this helps to keep things steady when building upwards.
Beyond that thought; not much more to say other than...
Now Go Be Adventurous... and build some edible houses today!