Insulating and refinishing exterior or 120 year old brick home.

Hi all, I'm new here so hopefully I'm in the right place and what I'm saying isn't stupid.

My wife and I live in a ~850 sq ft house with our two dogs and a cat in eastern Missouri. The house is solid brick masonry that is 3 wythes thick. I have talked to a number of contractors and they all suggest insulating from the inside, largely because it's what they're familiar with it seems. Now, the house is pretty small and I'd notice the space, plus there would be a ton of thermal bridging. The only exterior insulation options I see for masonry appear to be EFIS systems which are done by companies which only offer services to businesses. Would it not be better to insulate from the exterior? I've read a number of building sciences articles indicating it would.

So what would be the best way to insulate a solid masonry building from outside? I'd considered something like EPS foam board and finishing over that with clapboard siding. I've also considered something like Larsen trusses filled with any number of insulation types. I suppose the trick would be to successfully fasten the boards with fasteners in the mortar joints, but I'm not sure exactly how that would be done. Has anyone done this? Am I daffy for thinking I should?

Some photos will help a lot.
The visual beauty , if it exists of course will disappear, also when heating the inside the walls will be heated also.
If you insulate the inside, bearing in mind space saving, the wall will not absorb any heat.
Here is a discussion about basements


From Insulation inside or outside
"Closed-cell spray foam is the best way to insulate concrete basement walls.
This is because it can achieve a higher R-value, along with excellent moisture resistance, with less thickness required.
It can fill in all the gaps and spaces thoroughly, giving you the best protection against moisture and air infiltration."

Thanks for the reply. I knew the question of brick beauty would come up. For what it's worth, it's been painted (even more unfortunately they painted it red), and there's no consistency to the composition or technique in the mortar joints whatsoever. The basement is fieldstone, limestone specifically. It's actually kind of a weird setup, as I'm in the city and the east side is basically right up on the street. I'll try to find photos of that to help with the visual.

I had considered that insulation on the outside would require me to heat the walls still, but I'm doing that anyway. Also heating isn't my biggest concern, winters in St. Louis are usually mild. On sunny days above 35 degrees the heat doesn't kick on but a couple of times anyway. But during summer, when the nights are in the 70's the brick just absorbs so much solar energy during the day it doesn't really cool down well. Presumably exterior insulation would mitigate that, but it's very possible I'm overestimating how much of an effect it would have.

  I always thought the insulation belonged on the outside of masonry walls.  Examples are hard to find but Nick Pine did his old stone house with outside insulation and had great results.  I think the aesthetics is propabably the biggest difficulty.  That said exterior insulation is available in Europe.  

More research for you

https://www.homebuilding.co.uk/advice/external-wall-insulation

https://m.youtube.com/watch?v=96WN8AtAvNg

I have built forges useing perlite and cement. I believe a 8 part perlite 1 part Portland cement and 1 part sand would make an insulating plaster. It is not very strong but should hold itself up an on a wall. About R2 per inch.  If search there are white papers on the web on strength and R value.  My memory says 1:1:1 is about 1200 # mix and it looses 100# with each increase in perlite.  I need to make some test bricks I remember 10:1:1 was light like Styrofoam.  Tom

Noah, I have a better grip of what you are talking about.
Shading the south side would be a good idea to keep the house cool in summer.
I suggest 2 inch steel battens vertically up the wall.
Then good quality insulation sheet or roll horizontally across the battens.
Then outside finish attached to the battens.
Keep the bottom and the top of the layer open so air can move up the wall and prevent it heating.

It works very well.