Replies

1. GBA Editor
   Martin Holladay | Feb 15, 2014 05:09am | #1

   Raj,
   You forgot to include two important pieces of information:

   1. Where are you located? (Which is to say, What is your climate zone?)

   2. Are the existing walls insulated or uninsulated?

   I'm assuming that this house is a wood-framed house with studs -- but you didn't tell us anything about the home's construction, so that assumption may be wrong.

   If the house has wood framing and the walls are uninsulated, the most cost-effective approach would be to install dense-packed cellulose between the studs.

   If it is impossible to insulate between the studs -- either because the house has a different type of wall construction, or because the stud bays are already insulated -- the least expensive way to proceed would probably be to install exterior rigid foam, although you might want to consider exterior mineral wool.

   For more information, see:

   How to Install Rigid Foam Sheathing

   Calculating the Minimum Thickness of Rigid Foam Sheathing

   Wrapping an Older House with Rock Wool Insulation

2. 
   mathewscm | Feb 15, 2014 08:57pm | #2

   Thanks Martin, this is helpful. The house is in PEI, Canada. yes, it's wood frame.