May be worth putting a thin brown wash over it, the brightness is ok but looks just too clean.
Otherwise spot on, nice size and you have to look close to see the windows and doors are on the outside.
Did the windows etc on some buildings of mine with four strips of balsa, matchsticks would also work, stuck on as a frame. Filler on the walls, not the window (put on with a brush after adding water to make it a thick paste).
Also not got any currently but many moons ago I used textured masonry paint as the base for this sort of thing over thick card, beige colour worked well as a sandy base, drybrush white and done. A lot less trouble than filler as well.
Nice size for a building though, tend not to base mine but it does make them last a lot longer