Hello all. I’m fairly new to CFD and CAD with only some slight experience with solidworks in the past. I am trying to analyse airflow around a part of downtown Vancouver for a grade 10 project. I found the model on the sketchup warehouse and imported it to AutoCAD. Unfortunately most of the buildings are not watertight and either are missing a base or have holes in the side of them. Is there any quick solution to this? Thickening all the walls and surfaces came to my mind but the times I have never found success in doing this (I have no idea how to use AutoCAD). Any sort of help would be greatly appreciated. I can email the model file as I do not know how to attach it in a thread.