I got gingerbread house cookie cutters for Christmas a few years ago, and had yet to make a gingerbread house from scratch!
I was already making some gingerbread cookies for a cookie exchange, so I doubled my recipe and cut out pieces for my gingerbread house. Because I used my usual recipe and not one intended for wee-house building, I think the cookie was softer than it should have been.
As far as frosting goes, I picked a recipe from a page with instructions on gingerbread house making. I think that I probably went a little bit overboard on whipping my frosting because it just would not form stiff peaks! Either way, it still worked well.