I customized a brick to be 6x1 studs and 5 heights to be the same height as Duplo door.
Added a window, chamfers filets e voila.
Customized version of http://www.thingiverse.com/thing:615256
Retouched with Fusion360.
Printer: Print Rite DIY
Infill: 10 - 15%
Printed in PLA.
Used 4 Perimeters and 4 Top/Bottom solid layers.
Make foto coming soon.
I play with electronics, kids toys, replacement parts, puzzles,...