The roof on our 1930s semi has finally given up the ghost and we are getting quotes on replacing it. I am a complete roof moron - would it be worth sticking a dormer/skylights/both whilst it is being done for a future loft conversion (which is looking likely, but 2/3 years time likely)? I am thinking this would save scaffolding costs and make the conversion an easier process.
Only if you're going to put the steels in at the same time, otherwise they'll just have to take the roof off again. I would get plans for the conversion drawn up and get building control round at appropriate points so that when you convert fully (under permitted development?) you can get sign off etc. might be worth contacting a loft conversion company and getting a quote for doing the shell (no stairs, floors or walls) and seeing how it compares to roof quotes.