Hi all. Newbie question regarding storm windows

[Zman]

Hi all
Our house is in western suburbs of Chicago.
I have a 2003 build house with builders grade vinyl windows. In our bedrooms we feel it to be cold near the windows and I don't want to replace the windows yet. I was researching on the options and found that storm windows will help. Either Interior or Exterior storm windows. Each one can be either Low-E glass or Plexiglas. I prefer exterior Plexiglas windows since I see water inside the room during downpours.

Can any one suggest me a good storm windows or any other choices (other than replacing all the windows).
I will prefer self install but open for pro install as long as the whole project is reasonable.
Approximate window size is 71 in wide X 58 1/4 in height (Qty 5).

Appreciate all the help I can get.

[Windows on Washington]

The descriptors of "builder's grade vinyl" and "exterior storm window" should probably be mutually exclusive.

I would be very concerned of trapped heat and ultimate deformation of the primary window when you are talking about builder's grade anything to be honest. Even if the storm is equip with Low-e, I would be very cognizant of too much trapped heat and premature failure of the vinyl window.

[HomeSealed]

+1. Especially if the prime window has low-e as well. Other factors:
-On plexiglass or lexan, I'd only consider that for interior use imo. Scratches very easily.

-More importantly, you mentioned water leakage in heavy rains. That is a major problem.
1) A storm of any type will not fix that, as it is likely a flashing issue around the window.
2) If you SEE water leakage in heavy rain, that doesn't mean that you don't have water getting into places that it should not (like inside your walls) even during normal or light rain.

I don't want to sound like a shady window sales guy here, but active water infiltration is something that requires immediate attention. I wouldn't spend a dime trying to upgrade the efficiency of these windows, I'd strongly recommend replacement so that leakage is addressed. If it is not in the budget at this time, most reputable companies have financing options that make things more palatable. You will save your home from additional potential damage, and also save the energy and increase comfort that you are already looking for... If you are looking for a boost in efficiency in the VERY short term until you can get that completed, put up the 3M window film on the interior and call it a day.

[Zman]

Thank you both for your input, I appreciate it.