Problem with curved faces

Im building this curved building and i have got to a point were i want to create some balconies. The balconies should just be regular rektangels that goes into the building so that they dont stick out of the building. The problem is that when it is a curved face i cant figure out how to do it. Is it possible?
PS: i have the same problem when i want to make windows


It looks as if you’ll need to use the Intersect Faces command to add windows and balconies to your curved wall. Make the wall a component, but don’t open it for editing. Draw the balcony in place where you want it on the wall. Extend the back edge so it penetrates the wall completely.
Select all the geometry for the balcony and go to Edit>Cut. Open the wall for editing and go to Edit>Paste in Place. Now, select everything–the wall and the balcony. Right-click and choose Intersect Faces>With Selection. Erase everything you don’t need to show the relationship between the wall and the balcony. Do the same for windows and doors.