Interior is partially set.
Beside the low-poly roof, I have given also a detailed i.e. high-poly roof. It is hidden. So, please unhide it if you want to render that as well.
Except this detailed roof all models have a total of around 5000 faces. But with this detailed Roof the total number of number of faces is as many as 711432.
So, it is up to you whether you will use the hidden roof. Only one thumbnail herewith is rendered with that roof.