Patio Door Replacement

We are seeking to replace our patio doors to our condo in a multi-unit building. The patio doors go to a private decked area in an internal courtyard of the building. They are for our unit’s sole use. The masonry opening will remain exactly the same. They are currently large casement window style swing out doors that we would seek to switch them out to sliding doors–the only change really being the operation for the doors’ opening. Also, we have three other means of egress. A front door to outside from the unit and two doors leading from the unit to the building. Might we need a permit? The building code suggests that for a window replacement, if the masonry cut out size is the same, you don’t need a permit. These are essentially large windows that you can walk through. Thanks for any help.