Search some modelling tutorials on Youtube.

I always find topics like this silly, you can't build interiors unless you have a LOT of modelling knowledge and experience in programs like 3DS Max.

In the download section  

I think I'll upload a blank scene2 that anyone can use in future.

I'm eager.. any secret screens you can PM me?  <img src="/wp-content/uploads/invision_emoticons/tongue.png" alt="" data-emoticon="" srcset="/wp-content/uploads/invision_emoticons/tongue@2x.png 2x" width="20" height="20">

John, no that's true but I could cut a model out of the scene.4ds (where the table model is stored, for example) if you need it.

Sounds good Samo, if you need me to script/build anything just let me know.

filedropper.com

No that one will be fine.

Hmm.. odd. Okay upload it and sent the scene2.bin over to me, I'll fix it.

Yeah, that's because the door is the child of the building. Only the parent shows when you click the whole model in the scene.4ds, but that's complicated. Can I see the back side view with the door properties box?

In that case the door IS a separate thing. Show me from the inside with the door selected.

Press Ctrl+S and you'll be able to select it on it's own. How did you know the name of the door if you couldn't select it?

Mafia World Editor (or Mafia Editor)

Ok, you want open 'false' and I need to see the door selected in MWE with the properties box open.