Make your own window?

I had a home built in September 2003 and have dual pane windows. Since the very first winter we have had major condensation on the inside glass, (not inside of the glass, but the part that is inside of the house). I called the builder to check it out, because there was ICE forming on my windows and the condensation covered over half of the window. They looked at it, but said that it may be because it was a new house and there may be moisture in the foundation. This problem should reduce over time and I shouldn't be worried about it. The next year, I had the same amount of condensation and ICE on my windows. We keep our heater at 70 degrees until we go to bed then it goes down to 65 degrees. We don't run a humidifier either. There is only 4 people in the house and we do not take long hot showers or do laundry everyday. I keep getting the same response from the builder that there is nothing that they can do, because they don't know why this is happening. What can I do to fix this problem? I have black mold on the window ledge inside of my house and do not want my family to get sick. Thank you

I'm getting ready to close on a house that needs some rehab and one thing is the front door. It's one of those "steel clad" doors, but it's plain, now window, like a back door might be. Is it possible to add a window to one of those? I'd rather spend a few bucks and some time than the $150 or so one of the "fan light" ones will probably set me back. Thanks in advance. frank