You should place the shingles above
those further down and thus work your way up to the top. Especially on the second photo it seems you went the opposite way.
Maybe using some more wood for the edges would look good. You could then hide the edges of the foamboard (on which the roof is glued which is visible on photo 2).
The wood stips on the floor could be placed closer to each other so you don't have any gaps. I can see one of them going up in the first photo. Maybe use something to fix them while drying next time to prevent them from bending.
I really like the greyish look on the inside of the house! It looks diry and rundown.
All in all a nice playable piece. Let's see the next one!