I'm planning to replace my old Velux skylight, which was here when I moved in September '99. I'll go with solar powered, venting, with blackout blinds (it's in the bedroom.)

This is on the 3rd floor of a 200 year old Philadelphia rowhome.

I have someone from the Velux-recommended local installation company coming out on Monday to give me an estimate. Is there anything I should know or ask or consider?