I went on my own path trying to build this but I highly suggest watching this https://www.youtube.com/watch?v=y1Hh2Wbyozo for some inspiration. Also I suggest that if you are making a low poly cabin then use smooth plastic and if you are making a realistic build use a texture pack; not the default textures. To prevent “rigid” cuts in your build change your lighting.
Unions are very useful for abstract shapes, and if the user does not want to use blender it’s a perfect thing to use. If they are used minimally for essential items, then the performance effect will be very limited.