Weather helps determine how much insulation you are going to place into a structure. On the other hand if the temperature were to stay around 60-70 year round then this structure would not have to be insulated as well as the one with the drastic temperature differences. The amount of energy that can be saved with the proper use of insulation, storm sash and storm doors can best be illustrated by house when built before the pre-energy crisis. This house, at the time it was built, had full insulation in the ceiling only. Storm sash and storm doors were installed on all windows and doors.
Installation is very critical in making a home more efficient.
The effectiveness of the insulation can depend on the workmanship of the carpenter. Compressed blankets of batts change the density and reduce the insulation value. Blown in insulation with too much air in the mixture results if fluffy application that's less dense than required. In time it settles and isn't thick enough to provide the desired R-value. Installing the batt or blanket under floors over crawl spaces with the vapor retarder facing the wrong way.