Batt Insulation for Existing Vented Attics Description Guide describing how to increase insulation in existing homes by installing batt insulation on the ceiling plane of a vented attic.
Blown Insulation for Existing Vented Attic Description Guide describing how to insulate a vented attic in an existing home using blown insulation added to the attic floor.
Ducts Buried in Attic Insulation Description This guides describes buried ducts in loose-fill attic insulation, a method that can only be used in dry climates.
Spray Foam Insulation Applied to Existing Attic Floor Description Guide describing how to apply spray foam insulation to ceilings in existing homes.
Unvented Conditioned Attic with Spray Foam Insulation Below Roof Deck Description Guide describing a method for insulating an unvented attic by spraying foam insulation along the underside of the roof deck.