Loft conversion - rear dorma... anyone had one done recently

[dern]

We've got a 4 bed semi and were considering getting a rear dorma type loft conversion done so had a couple of questions of anyone who had had one done recently. I know we need to get someone in to give us an estimate but we're just looking for a shall we/shan't we idea of how much money/disruption. What we want is one big room, dorma to the rear (full width of the house), no bathroom or anything like that. We want to use it as a spare bedroom with a sofa bed in it but mainly as somewhere for the kids to play with loads of floor space. Has anyone had anything like this done recently and if so how long did it take to finish, how much roughly did it all cost and did what you ended up with live up to your expectations?

Thanks,

Mark