Dollhouse Window created for my daughters dollhouse. 

Scale accordingly to the size of your needs. There is an inner and outer frame and as long as they are scaled together, they should fit tightly together. Z-axis (height) should be scaled accordingly to the thickness of your wall. They can be put together and then taken apart again and again. I've done this over 100 times with one window and there is no visible wear and tear, yet they fit so tightly together that they won't fall apart on their own.