On the subject of skylights, I differ. My present home has three skylights, two of them being the operable sort. A previous abode had an inoperable skylight, which always leaked. I concluded from that experience that skylights always leak. Not so. When I bought this house one of the skylights leaked. I learned that the two operable ones had been installed incorrectly--the remodeler had ignored the (clearly stated) manufacturer's instructions and had NOT provided the proper pitch. I had a contractor do so and caulk them adequately, and VIOLA! no leaks.
It can be difficult to retrofit this, however, because the junction of the skylight and the roof is important. GEORGE, I would contact the manufacturer of your existing skylight and ask if they make any operable ones the same size as your existing one, and also how difficult he thinks it would be to make the change.
BTW, my skylights were made by Andersen Windows, and even though the installation error was clearly not Andersen's fault, they gave me new sashes (the portion of the skylight which contains the glass) free of charge. I had to pay my contractor to do the modification, however. So I must say that Andersen went the extra mile and then some.
BTW #2, I couldn't LIVE in this house without those two operable skylights! The extra ventilation makes a huge difference.
BTW#3: some models have a screen to keep out the flying insects.
