HVAC Ducts Shall Not Be Run within Exterior Walls Description Guide describing the use of building cavities as supply or return ducts.
Spray Foam Insulation Applied over the Siding of Existing Exterior Walls Description Guide describing how to install spray foam on the exterior of the existing home after framing over the existing siding.
Spray Foam Insulation for Cavities of Existing Exterior Walls Description Guide describing how to insulate the walls of an existing home with spray foam insulation.