Homes built prior to the 1950's rarely had insulation. Insulation can be added to the exterior walls, attic and crawlspace to help with the drafty rooms or cold floors.
The exterior walls can be insulated with Dense Packed Cellulose or Fiberglass. For homeowners who are looking for additional insulation with better air sealing qualities Dr. Energy Saver Delaware offers iFoam eXP. iFoam eXP is a expanding injection foam that forms to the cavity. iFoam eXP is a true foam and is not a pre-expanded water-based tri-poloymer. Unlike the tri-poloyer foams iFoam eXP will not shrink or cause water damage to walls.
Problems with cold floors over crawlspaces are fixed with CleanSpace and SilverGlo Insulation on the foundation walls. Spray foam in the rim joist helps prevents the drafts.