for home renovation, is it better to install insulation on the inside or outside?

Neil Richardson Published: Jan. 29, 2019, 4:09 p.m.Last updated: July 3, 2019, 1:08 p.m.

Hi, I have a 1955 red all brick bungalow. the interior walls are a very thick plaster board (maybe 1" or more thick). I want to take the walls down to the studs and insulate. There is family debate about taking the brick off the outside. If we keep the brick what is the best insulation (from the inside) between the studs on the outside walls? We will be putting up drywall to finish the room.


Responses (1)

Ecohome Feb. 12, 2019, 9:38 a.m. Reply


Bricks as an exterior finish is 3 times the cost and 3 times the value of any other cladding, so I wouldn’t get rid of it on a whim. If you really can’t stand the look of it or its crumbling, I would make those the deciding factors. If you’re doing an interior renovation anyway then I would say you are best to insulate from the inside, and there are few methods. First, have the wiring checked by a licensed electrician to be sure its safe and up to code.

As for insulating, there are a few methods you could choose from:

If you have a 2x6 wall and don’t want to lose any interior space, I would recommend spray foam, it has the highest per-inch R value. If you have only a 2x4 wall (which unfortunately is almost certainly the case), It would be very wise to sacrifice some interior space to accommodate thicker insulation.

Spray foam provides the insulation, vapour barrier as well as an air barrier, so it’s a nice all in one solution, though we would recommend you source one of the brands that have moved to lower GWP blowing agents which to our knowledge at the moment are Demilec and Elastochem.

Aside from spray foam, you could fill exterior cavities with batt insulation, dense packed cellulose, you could also add rigid foam panels, Rockwool panels etc, there are many methods. You need to ensure that whatever method you chose is airtight and does not trap moisture inside. The following are a few pages that may help you make those decisions. Have a read through these, and as you get closer to making a decision feel free to drop a line when you have a short list. It has been very busy times lately so we can be sure to reply quicker with a follow up, sorry it took a while to get back to you.