... or have had quotes for one? If so I'm just wondering what the costs involved were? I'm thinking about 1.5-2 meters accross and 1 meter'ish deep I guess. the extra head room would be really useful.

I see you can buy a velux double dormer window setup for about £2-2.5k but wouldnt have a clue how much installation might be.

If you've DIY'ed one, how big of a Pain in the butt was it and how long did it take???

If any builder sorts out there do this for a living any info would be great!