Great questions. While manufactured homes typically use considerably more energy than site-built homes because of lower insulation levels (the bad news), the savings from insulation and air sealing improvements are typically very good (the good news)!

So, sorry to hear your walls feel cold and seem thin, but that might be exactly the case. There are many differences between manufactured homes built before 1976 and those after as a result of changes to the HUD code -- with those built after benefiting from thicker wall cavities able to hold more insulation -- so hopefully your home is less than thirty years old.

Now the good news again. Fiberglass insulation can be blown into wall, roof and "belly" cavities and is the preferred method in most regions of the country because it absorbs less moisture than other materials.

To take action on insulation and air sealing your home, you should take a look on the EnergySavvy energy contractor listings for your area. They should be able to help you figure out the cost-effectiveness and comfort impact of different upgrades based on your monthly utility bills.

Also, an energy audit can also be a very helpful tool to identify the least expensive and most beneficial steps to take to decrease the air leakage and maximize the indoor comfort of your home.