I Can Smell My Neighbors Cooking In One Of My Rooms

[RehanSaeed]

My neighbors kitchen extract vent is beside the flat roof of my ground floor extension and the smells can somehow be smelt inside one room of my house. I closed all windows and trickle vents but found that in one corner of the room the smell was literally coming up through the floor. I know that the space in my flat roof and the floor of the first floor bedroom are connected, so I think the smell is being sucked up through the flat roof, into the floor of the main house and up through the floor boards and into the bedroom.

I can't see any vents in my roof or the overhang of the front of the flat roof, so I'm not sure where the air is getting in from. I need to have a word with my neighbor but what can I suggest to him as a solution?