Expanded room is partly "outside"

[duanethebathtub]

Hi - I saw this posted in various places on the Internet, but don't seem to find a resolution.

 

I broke down part of the wall in the apartments in Westside accross from the middle gas station and expanded the room.

 

It's all enclosed and even put a roof over the top.   However, it thinks the area I added on is outside.

Is there a fix for this?

 

Thanks.

[Enoahe]

Split the room in half. Wooden frames will do. Check if at least one part of a room considered as 'inside'. Then move your frames gradually forward tile by tile until all the room became 'inside'.

This way I've managed to fix it couple times.