Amazing work Zephyris!
Little bash script and nml file to create a house grf to view those houses in game
Install ImageJ, install NML, extract the zip file and run the script "run". It'll create macrobuildings.grf containing a few houses. These houses will be available in all climates in all town zones to ease testing. You can change the amount and height (in number of stories) of houses the script generates in the run script (line 19+20).
I've slightly altered Zephyris ImageJ script so it accepts a few parameters when started via the commandline, so avoid running the macro manually every time you want to generate new houses.