Good afternoon,   Ok, if any of you guys could provide any advice, I'd be more than grateful! Seems the last few hours spend on google have provided different result.   Essentially, I am a Joiner to trade and live (or did) in a cottage(not listed) which only has one entrance/exit. In bonny Scotland. Our bedroom to the rear of the house had two windows within. I did have issues with one of the windows, leeking etc and decided to replace it with a singular patio door. I also fo