Along with Insulation, we install double pane windows and insulated doors. Conduction and infiltration are two of the major problems in older homes. The insulation helps primarily with the conduction issues, the double pane windows and insulated doors deal primarily with infiltration. If you have been in a house where air is coming in, no matter what the temperature is set at, it will feel cool. It takes high temperatures in the house just to feel comfortable. So, stopping the infiltration is essential. The insulation in the walls also help stopping infiltration. Most of the older homes have balloon walls, which means that there are no floor stops running out to meet the outside walls. Air can flow up the walls and into rooms via the baseboards and wall receptacles and light switches. The insulation serves to help reduce the amount of air coming up the walls. The walls and doors do reduce conduction some, but to date their R-value is quite low.