Blown-in insulation is, in many cases, the easiest and most efficient means of insulating a house against energy inefficiency and cold and, in its modern form, has no disadvantages when weighed against other types of insulation. It conforms to its space and does not shed into the air.
Very old blown-in insulation may be fortified with shredded newspaper and other substances. These old formulations are virtually never used in modern insulation but, when present, they represent a real danger of fire.
Batts are unwieldy, shed fibers and may be hard to install. Blown-in insulation can be installed through orifices as small as an inch across and give houses a tighter seal.