According to bud-- :
car crash wrote:
I noticed in a new home I recently bought in Ontario that I have a
bathroom outlet that was installed in the wall that is also the wall
to the outside. Now in the last house I had, I asked the builder to
do this but he said that it was against code to do that. So why is it
this builder can now install a wall outlet on the wall that is the
outside wall as well ? Is there a violation of the code by installing
a wall outlet on a outside wall ?
Thanks.


Just a guess: When you put an outlet on an outside wall you are
penetrating the vapor barrier on the inside-house side of the insulation
and reducing the insulation at that point. Both are undesirable.
Breaking the vapor barrier can allow humid inside air into the
insulation where it can freeze and produce both thermal and water
problems.

Canadian building codes require that boxes installed in exterior
walls MUST be properly sealed to the vapor barrier. This is often
done by "bagging" the box in a chunk of vapor barrier, and when
the sheet vapor barrier is installed, they puncture it over the box,
and the edges of the box bag are pulled thru and tuck-taped to the
sheet. There remains only some small penetrations where the cables
were punched thru the "bag".

They also make plastic boxes with "vapor barrier" tabs on them
for the same purpose.

Other than that, there are no unusual restrictions on interior
outlets/switches mounted on the inside of exterior walls.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.