builders' paper at windows and doors

Oops, another one. Now I'm framing and I find none of the documentation I have (arch drawing, web page from window mfr, product approval) gives me the rough opening for the 24x36 single hung aluminum windows. Or am I being dumb and it's 24x36? Any way to say without the window in hand?

We looked at a 6-year old Log house today to possibly purchase and found a lot of condensation on all the windows. Some facts we know about the situation: 1. The house seemed nearly empty with the inside temperature of about 65-68F 2. A cold day in Alaska. Outdoor temperatures were -30F 3. the house has three separate heating systems: 1) ground floor with hot water circulating in tubes under the flooring, 2) second floor has radiant heat, 3) a gas stove on the first floor. 4. The design is an open space all around the house 5. All window were nearly equally covered with ice in the bottom section of the window (with visible mold under the ice) 6. The gas stove heater draws outside air for combustion We understand the high difference in outdoor/indoor tempartures and the fact the the house is nearly empty may play a role in the excessive condenstation. The question is.... what do we need to ask and what do we need to change to remedy the situation.