Interior insulation / Discussions

...interior walls of new tongue and groove.  However is there a way we could keep the interior as it is, and insulate on the outside? We then have to figure out a way to hide the wiring.  It is located in Ontario where winters can vary between freezing and -20.  Thank you! To turn a 3 season cottage into a 4 season perman...

...insulation panels from Legalett that have rails on the interior of the foam so you can attach them with short screws, then attach the strapping to the same rail with more short screws, so you have no thermal bridging. It also comes in a variety of thickeness. Also Cascadia clips is another exterior insulation fastening...