That is a good question. I have never come across a situation with the egress window under the patio door exit. It definitely presents a challenge that would require further investigation. I would check with your township, borough, or any other governing agency in regards to building codes and any stipulations for the access to the egress window, as well as any exterior improvements off of your patio door as you may need permits to make any exterior changes that provide for the safe use of both the patio door and egress window. You would want to make sure you're within the recommended guidelines for such. If you have an HOA I would also check with them as you may also need their approval prior to any exterior changes to your home. Once you get all of the information regarding what is allowable and what is not, you can proceed with a good plan. Good Luck!

Thank you for your response. This sounds like an uphill battle!!