I live in a condo with two 2x4 skylights. My sloped roof is being replaced
soon, and I'm given a choice of either flat or dome. The cost is almost the
same, with the domed ones slightly less expensive.

The dome is said to be manufactured by Thermo-Vu, which was taken over by
Velux last January. The flat is made by Velux itself.

The main benefits with going with bubble plastic:

1) I'm led to believe that the inner frame is already colored white, so I
would not need to arrange to have the association come inside the condo to
paint the inner frames (which are well out of my reach even with my ladder).

2) Since these skylights are in bathrooms, I'm concerned about mold and
mildew due to condensation when taking showers (which happens even with the
fan running). I'm led to belive that these skylights do NOT have a wooden
frame, so there would be no worry about moisture
from shower condensation damaging the wooden frame.

3) supposedly domed units are quieter when it rains and these bathrooms are
close to rooms I work and sleep in

4) Domed supposedly get less exterior dirt accumulation than flat (and I
would never be able to go up on the roof to clean the skylight).

5) Snow won't pile up on domed the way it does on flat. Not too worried
about this, though, since these are, after all, installed above bathrooms
and they also face the south.

The benefits of flat glass:

1) Said to be more durable than plastic, but the plan is to replace the
skylights again when another roof is put on in 20 years. (maybe the
durability issue is only a concern if I'm going to be here more than 5
years)

2) Said to be more energy efficient than plastic (but I don't know the exact
specs of either the flat or the domed)

By the way, One website even claims that plastic domed skylights are not
completely sealed. I'd like to know what they mean by that, since they have
to be in order to prevent water leakage.

3) glass won't fade or deteriorate over time (but may get more dirt
accumulation than domed)

Which of the two do you think I should choose? Would I be crazy to go with
domed to avoid the hassle of arranging to paint the interior frame, to avoid
potential mold/mildew problems of a wooden inner frame?

By the way, is any one of the two (flat or domed) more prone to leakage?

Thanks,

J.