Print the windows with 0.2mm layer height and scale them down to 97% or 98 % on x and y. When you make them half the thicknes on z, use 0.1mm layer height.
Scale the upper part up to 102-106%
No supports needed
The author remixed this model.
It is the same model but I made holes that goes trough the top part so you can print it witout supports. It was really hard to get them out of the holes where bottom and top part a sticked together
And i added a tealight hole that fits :-)