Blocking up external door

Hi, I have sliding patio doors and a regular door leading out of my kitchen. I need some extra space and want to block half way up the door and have a window fitted above. What type of person would be able to do this? I'm thinking it's a pretty small job and builders might not be interested. Many thanks

I am sure there are plenty of small (one man) size builders out there who would snatch your arm off for a job like that. Just make sure you pick one who is competent and legitimate.