p>You can for sure insulate the exterior of a painted brick house, in fact that would probably help preserve the bricks. <a href="/guides/2207/is-painting-bricks-a-good-idea-and-which-paint-is-best/" target="_blank">Be very careful when painting bricks to choose the right materials </a> since most paints will  traps moisture, and in a cold climate like Chicago, the freeze / thaw cycle can cause them to crack. So insulating the exterior of  a painted brick wall is actually a good idea to help protect them.</p> <p>When insulating the exterior of an existing house we often recommend Rockwool, it’s a recycled mineral wool rigid insulation , read more here – </p> <p><strong><a href="/guides/2254/polyisocyanurate-foam-is-a-hot-new-building-product-learn-where-and-where-not-to-use-it/" target="_blank">The difference between Polyiso, EPS &amp; XPS Foam Insulation &amp; Styrofoam</a></strong></p> <p>Rockwool isn’t harmed by moisture and it lets moisture move right through it, which is a very good thing to use for an exterior insulation renovation project since it doesn’t trap moisture in any wall system. You could apply Rockwool (rigid Comfortboard, not batts) then a weather barrier / air barrier, then strapping and your final siding.</p> <p>The only thing that might prevent you from doing this are municipal bylaws, which sometimes in older neighborhoods they often want to maintain the community aesthetics.</p> <p>One thing we would strongly urge you to do, would be to complete the job, and do all the surfaces including the foundation. If you insulate the bricks from a few feet up and don’t do the foundation, there will be so much thermal bridging from the warmer bricks to the colder foundation that a lot of your efforts will be undone in a way. It would be a bit like buying an awesome new winter coat, but then only wearing a pair of shorts. You need to complete the deal. </p> <p>Here are a few other pages that you should check out to make sure this works out properly – </p> <ul> <li><a href="/guides/2246/how-to-install-siding/" target="_blank">How to install siding so walls can dry</a></li> <li><a href="/guides/2219/weather-barriers-what-they-do-and-how-to-install-them/" target="_blank">Choosing the right weather barrier </a></li> </ul