Hello all, I need a bit of advice because I really dont know where to start. We live on the first floor of a victorian terrace conversion block of flats. It's a leasehold and the freeholder owns the ground floor flat. On the other side of our bedroom is the roof of the ground floor flat. We would like to (somehow) turn this into a roof terrace by putting a door in the bedroom leading to the roof. Our neighbors have done this on both sides of us so I think it should be ok. BUT there are two skylights at one end of the roof. My questions are these:

1. due to the skylights, is this whole thing a no-go?
2. what order should we be speaking to people? Architect (for structural soundness etc)/builders/solicitors/flat owner etc?
3. What type of planning permission might we need?
4. What should we expect to pay for all of this?!

Thanks very much for any advice!