I've recently purchased house that is about 4 years old. It has a garage attached to the side of the house with the back half of the garage being in the back garden. Its a single storey with a slanted roof and is single brick. I'd like to have a door (probably PVC) put in the side of the garage so that I can access it from the back garden. From what I've read a lintel would need to be fitted but I'm unclear about whether this would be classed as notifiable work and also from the corner of the wall how far do you have to leave before the door can be fitted ? Before I decide whether this should go ahead I wanted to know the considerations. Any advice would be helpful.