Is it possible to change exterior door hinges with some sort of "extension" hinge so that the door can stick out beyond the brickwork and enable the door to open 180 degrees? It is a UPVC double glazed door onto a decking.
Depends on how far your door is inset from the outer face of the external wall. I've seen hinges which will give you about 2-3 inches, but any more than that you'd probably have to move the door frame outwards so that the hinge pivot point is closer to the outside of the wall.
I found your query through an internet search and wondered if you found anywhere that sells extended UPVC hinges that will allow the door to open 180 degrees whilst being set back from the brick by 1.5 inches.
My UPVC front door was fitted by Starglaze several years ago but I now notice that the screws holding it to the frame have worked loose on the hinges. Trouble is I can't seem to open the hinge to tighten them, it is presumably sealed for security. Are there special tools for this or do I need to call in the manufacturer?
Very difficult without looking at your door as they are so many difference type of UPVC doors,sometimes they are special tools but you can buy them from a good tools shop.Normally most doors use a small allen key hidden somewhere and all UPVC doors are adjustable.