

A replacement skylight typically runs $1,200–$2,500 installed, depending on size and type. A new skylight in a roof with no existing opening costs more because of the framing and interior shaft. Free estimate after a look at the roof.
Not always. If the glass is clear and the unit is sound, re-flashing often solves it. If the glass is fogged or the frame is deteriorated, replacement is the better fix.
Older ones can. Modern skylights with low-E, argon-filled glass block most of the heat while letting the light through.
Yes — curb-mounted skylights are designed for flat and low-slope roofs and we flash them into EPDM or TPO membranes.