Function

• The type of insulation a home uses can have a huge impact on energy use and costs, reports the government's EnergyStar website. Home insulation creates barriers to prevent heat from seeping in and out of the home through windows, cracks, doors and anything else that induces air flow. Unusually high utility bills are a sign that a home has poor insulation.
  
  

Types

• The most common types of insulation are batt and brown fiberglass, foam boards and spray foam, according to EnergyStar. Some insulators use metallic foil to reflect heat back into the environment. The type of insulation does not matter so much as its "R-value," how well the insulation resists heat flow. A better insulator will possess a higher R-value.
  
  

Considerations

• Insulating a home does not just mean using a better material. Even the best insulators cannot work well if the house has leaks and cracks that bring in too much airflow, according to EnergyStar. Certain parts of the house require different levels of insulation, so houses should have multiple types of insulation. The most common area of the house with the most energy-saving potential is the attic.
  
  

Geography

• The area of the country where the house is located has the biggest impact on how much insulation a home should have, balanced with cost effectiveness. The typical home attic already contains 3 to 4 inches of insulation. Most homes need an R-value of 25 to 38. Homes in colder climates in the north and northeast need a total R-value of 49 to 60.
  
  

Warning

• EnergyStar claims that before purchasing more insulation, homeowners should seal up air leaks in door frames and windows with caulk or weather stripping. However, newer homes may become to tightly sealed and trap in fumes from gas burning appliances, or reduce oxygen flow. A home energy rater can detect leakage levels to determine if a house needs more ventilation.